diff --git a/retroshare-gui/src/gui/Posted/PostedItem.h b/retroshare-gui/src/gui/Posted/PostedItem.h
index 94bb12ed7..7bb920a6c 100644
--- a/retroshare-gui/src/gui/Posted/PostedItem.h
+++ b/retroshare-gui/src/gui/Posted/PostedItem.h
@@ -49,7 +49,7 @@ public:
 	const RsPostedPost &getPost() const;
 	RsPostedPost &post();
 
-	std::string uniqueIdentifier() const override { return "PostedItem " + mMessageId.toStdString(); }
+	uint64_t uniqueIdentifier() const override { return hash_64bits("PostedItem " + mMessageId.toStdString()); }
 protected:
 	/* FeedItem */
 	virtual void doExpand(bool open);
diff --git a/retroshare-gui/src/gui/common/RSFeedWidget.cpp b/retroshare-gui/src/gui/common/RSFeedWidget.cpp
index de18e49e0..be8c1215d 100644
--- a/retroshare-gui/src/gui/common/RSFeedWidget.cpp
+++ b/retroshare-gui/src/gui/common/RSFeedWidget.cpp
@@ -179,7 +179,7 @@ void RSFeedWidget::addFeedItem(FeedItem *feedItem, Qt::ItemDataRole sortRole, co
 	QTreeWidgetItem *treeItem = new RSTreeWidgetItem(mFeedCompareRole);
 
 	treeItem->setData(COLUMN_FEED, sortRole, value);
-	treeItem->setData(COLUMN_IDENTIFIER, Qt::DisplayRole, QString::fromStdString(feedItem->uniqueIdentifier()));
+	treeItem->setData(COLUMN_IDENTIFIER, Qt::DisplayRole, QString("%1").arg(feedItem->uniqueIdentifier(),8,16,QChar('0')));
 
 	ui->treeWidget->addTopLevelItem(treeItem);
 	ui->treeWidget->setItemWidget(treeItem, 0, feedItem);
@@ -207,9 +207,9 @@ void RSFeedWidget::addFeedItem(FeedItem *feedItem, const QMap<Qt::ItemDataRole,
 	for (it = sort.begin(); it != sort.end(); ++it) {
 		treeItem->setData(COLUMN_FEED, it.key(), it.value());
 	}
+	treeItem->setData(COLUMN_IDENTIFIER, Qt::DisplayRole, QString("%1").arg(feedItem->uniqueIdentifier(),8,16,QChar('0')));
 
 	ui->treeWidget->addTopLevelItem(treeItem);
-	treeItem->setData(COLUMN_FEED, Qt::DisplayRole, QString::fromStdString(feedItem->uniqueIdentifier()));
 	ui->treeWidget->setItemWidget(treeItem, 0, feedItem);
 
 	feedAdded(feedItem, treeItem);
@@ -438,10 +438,10 @@ void RSFeedWidget::feedItemDestroyed(FeedItem *feedItem)
 		emit feedCountChanged();
 }
 
-QTreeWidgetItem *RSFeedWidget::findTreeWidgetItem(const std::string& identifier)
+QTreeWidgetItem *RSFeedWidget::findTreeWidgetItem(uint64_t identifier)
 {
     std::cerr << "FindTreeWidgetItem: looking for \"" << identifier << "\"" << std::endl;
-    QList<QTreeWidgetItem*> list = ui->treeWidget->findItems(QString::fromStdString(identifier),Qt::MatchExactly,COLUMN_IDENTIFIER);
+    QList<QTreeWidgetItem*> list = ui->treeWidget->findItems(QString("%1").arg(identifier,8,16,QChar('0')),Qt::MatchExactly,COLUMN_IDENTIFIER);
 
     if(list.empty())
     {
@@ -495,7 +495,7 @@ void RSFeedWidget::withAll(RSFeedWidgetCallbackFunction callback, void *data)
 	}
 }
 
-FeedItem *RSFeedWidget::findFeedItem(const std::string& identifier)
+FeedItem *RSFeedWidget::findFeedItem(uint64_t identifier)
 {
 	QTreeWidgetItemIterator it(ui->treeWidget);
 	QTreeWidgetItem *treeItem=NULL;
@@ -515,7 +515,7 @@ FeedItem *RSFeedWidget::findFeedItem(const std::string& identifier)
         //    if(feedItem->uniqueIdentifier() == identifier)
         // causes a crash. I dont know why! If someone ever finds why, please tell me.
 
-        std::string id = feedItem->uniqueIdentifier();
+        uint64_t id = feedItem->uniqueIdentifier();
 
         std::cerr << "Comparing \"" << id << "\"";
         std::cerr << " to " << identifier << "\"" << " pthread_t = " << pthread_self() << std::endl;
diff --git a/retroshare-gui/src/gui/common/RSFeedWidget.h b/retroshare-gui/src/gui/common/RSFeedWidget.h
index 147c95595..bc38adf84 100644
--- a/retroshare-gui/src/gui/common/RSFeedWidget.h
+++ b/retroshare-gui/src/gui/common/RSFeedWidget.h
@@ -71,7 +71,7 @@ public:
 	bool scrollTo(FeedItem *feedItem, bool focus);
 
 	void withAll(RSFeedWidgetCallbackFunction callback, void *data);
-	FeedItem *findFeedItem(const std::string &identifier);
+	FeedItem *findFeedItem(uint64_t identifier);
 
 	void selectedFeedItems(QList<FeedItem*> &feedItems);
 
@@ -98,7 +98,7 @@ private:
 	void connectSignals(FeedItem *feedItem);
 	void disconnectSignals(FeedItem *feedItem);
 	FeedItem *feedItemFromTreeItem(QTreeWidgetItem *treeItem);
-	QTreeWidgetItem *findTreeWidgetItem(const std::string &identifier);
+	QTreeWidgetItem *findTreeWidgetItem(uint64_t identifier);
 	void filterItems();
 	void filterItem(QTreeWidgetItem *treeItem, FeedItem *feedItem);
 
diff --git a/retroshare-gui/src/gui/feeds/ChatMsgItem.h b/retroshare-gui/src/gui/feeds/ChatMsgItem.h
index 6dad0d215..fe946a4b9 100644
--- a/retroshare-gui/src/gui/feeds/ChatMsgItem.h
+++ b/retroshare-gui/src/gui/feeds/ChatMsgItem.h
@@ -37,7 +37,7 @@ public:
 
 	void updateItemStatic();
 
-    virtual std::string uniqueIdentifier() const override { return "ChatMsgItem " + mPeerId.toStdString(); }
+    virtual uint64_t uniqueIdentifier() const override { return hash_64bits("ChatMsgItem " + mPeerId.toStdString()); }
 protected:
 	/* FeedItem */
 	virtual void doExpand(bool /*open*/) {}
diff --git a/retroshare-gui/src/gui/feeds/FeedItem.cpp b/retroshare-gui/src/gui/feeds/FeedItem.cpp
index 19cfdbf72..955298a24 100644
--- a/retroshare-gui/src/gui/feeds/FeedItem.cpp
+++ b/retroshare-gui/src/gui/feeds/FeedItem.cpp
@@ -18,10 +18,11 @@
  *                                                                             *
  *******************************************************************************/
 
+#include <iostream>
 #include "FeedItem.h"
 
 /** Constructor */
-FeedItem::FeedItem(QWidget *parent) : QWidget(parent)
+FeedItem::FeedItem(QWidget *parent) : QWidget(parent), mHash(0)
 {
 	mWasExpanded = false;
 }
@@ -43,3 +44,18 @@ void FeedItem::expand(bool open)
 		mWasExpanded = true;
 	}
 }
+
+uint64_t FeedItem::hash_64bits(const std::string& s) const
+{
+    if(mHash == 0)
+	{
+		mHash = 0x01110bbfa09;
+
+		for(uint32_t i=0;i<s.size();++i)
+			mHash = ~(((mHash << 31) ^ (mHash >> 3)) + s[i]*0x217898fbba7 + 0x0294379);
+
+        std::cerr << "Producing hash " << std::hex << mHash << std::dec << " from string \"" << s << "\"" << std::endl;
+	}
+
+	return mHash;
+}
diff --git a/retroshare-gui/src/gui/feeds/FeedItem.h b/retroshare-gui/src/gui/feeds/FeedItem.h
index d377fb027..7cd6808a1 100644
--- a/retroshare-gui/src/gui/feeds/FeedItem.h
+++ b/retroshare-gui/src/gui/feeds/FeedItem.h
@@ -41,17 +41,19 @@ public:
      * \return returns a string that is unique to this specific item. The string will be used to search for an existing item that
      * 			would contain the same information. It should therefore sumarise the data represented by the item.
      */
-    virtual std::string uniqueIdentifier() const =0;
+    virtual uint64_t uniqueIdentifier() const =0;
 protected:
 	virtual void doExpand(bool open) = 0;
 	virtual void expandFill(bool /*first*/) {}
 
+    uint64_t hash_64bits(const std::string& s) const;
 signals:
 	void sizeChanged(FeedItem *feedItem);
 	void feedItemDestroyed(FeedItem *feedItem);
 
 private:
 	bool mWasExpanded;
+    mutable uint64_t mHash;
 };
 
 #endif
diff --git a/retroshare-gui/src/gui/feeds/GxsChannelGroupItem.h b/retroshare-gui/src/gui/feeds/GxsChannelGroupItem.h
index 5c51b396a..1a0c56a70 100644
--- a/retroshare-gui/src/gui/feeds/GxsChannelGroupItem.h
+++ b/retroshare-gui/src/gui/feeds/GxsChannelGroupItem.h
@@ -41,8 +41,7 @@ public:
 	~GxsChannelGroupItem();
 
 	bool setGroup(const RsGxsChannelGroup &group);
-
-    std::string uniqueIdentifier() const override { return "GxsChannelGroupItem " + mGroup.mMeta.mGroupId.toStdString() ; }
+    uint64_t uniqueIdentifier() const override { return hash_64bits("GxsChannelGroupItem " + groupId().toStdString()) ; }
 protected:
 	/* FeedItem */
 	virtual void doExpand(bool open);
diff --git a/retroshare-gui/src/gui/feeds/GxsChannelPostItem.cpp b/retroshare-gui/src/gui/feeds/GxsChannelPostItem.cpp
index d7a807d59..cdb4eeaf2 100644
--- a/retroshare-gui/src/gui/feeds/GxsChannelPostItem.cpp
+++ b/retroshare-gui/src/gui/feeds/GxsChannelPostItem.cpp
@@ -71,6 +71,7 @@ void GxsChannelPostItem::init(const RsGxsMessageId& messageId,const std::set<RsG
 
 	setup();
 
+    mPost.mMeta.mMsgId = messageId; // useful for uniqueIdentifer() before the post is loaded
 	mLoaded = false ;
 }
 
diff --git a/retroshare-gui/src/gui/feeds/GxsChannelPostItem.h b/retroshare-gui/src/gui/feeds/GxsChannelPostItem.h
index a68c25e5d..8b9d21c57 100644
--- a/retroshare-gui/src/gui/feeds/GxsChannelPostItem.h
+++ b/retroshare-gui/src/gui/feeds/GxsChannelPostItem.h
@@ -53,7 +53,7 @@ public:
 	//GxsChannelPostItem(FeedHolder *feedHolder, uint32_t feedId, const RsGxsChannelPost &post, bool isHome, bool autoUpdate);
 	virtual ~GxsChannelPostItem();
 
-    virtual std::string uniqueIdentifier() const override { "GxsChannelPostItem " + mPost.mMeta.mMsgId.toStdString() ; }
+    uint64_t uniqueIdentifier() const override { hash_64bits("GxsChannelPostItem " + mPost.mMeta.mMsgId.toStdString()) ; }
 
 	bool setGroup(const RsGxsChannelGroup &group, bool doFill = true);
 	bool setPost(const RsGxsChannelPost &post, bool doFill = true);
diff --git a/retroshare-gui/src/gui/feeds/GxsCircleItem.cpp b/retroshare-gui/src/gui/feeds/GxsCircleItem.cpp
index c7175d4d4..aa161cde4 100644
--- a/retroshare-gui/src/gui/feeds/GxsCircleItem.cpp
+++ b/retroshare-gui/src/gui/feeds/GxsCircleItem.cpp
@@ -167,9 +167,9 @@ void GxsCircleItem::setup()
 
 }
 
-std::string GxsCircleItem::uniqueIdentifier() const
+uint64_t GxsCircleItem::uniqueIdentifier() const
 {
-    return "GxsCircle " + mCircleId.toStdString() + " " + mGxsId.toStdString() + " " + QString::number(mType).toStdString();
+    return hash_64bits("GxsCircle " + mCircleId.toStdString() + " " + mGxsId.toStdString() + " " + QString::number(mType).toStdString());
 }
 
 void GxsCircleItem::removeItem()
diff --git a/retroshare-gui/src/gui/feeds/GxsCircleItem.h b/retroshare-gui/src/gui/feeds/GxsCircleItem.h
index f8c66edbb..a45114ed6 100644
--- a/retroshare-gui/src/gui/feeds/GxsCircleItem.h
+++ b/retroshare-gui/src/gui/feeds/GxsCircleItem.h
@@ -52,7 +52,7 @@ public:
 	GxsCircleItem(FeedHolder *feedHolder, uint32_t feedId, const RsGxsCircleId &circleId, const RsGxsId &gxsId, const uint32_t type);
 	virtual ~GxsCircleItem();
 
-    std::string uniqueIdentifier() const override;
+    uint64_t uniqueIdentifier() const override;
 	void loadRequest(const TokenQueue *queue, const TokenRequest &req);
 
 
diff --git a/retroshare-gui/src/gui/feeds/GxsForumGroupItem.h b/retroshare-gui/src/gui/feeds/GxsForumGroupItem.h
index a6cf6e129..87bffa022 100644
--- a/retroshare-gui/src/gui/feeds/GxsForumGroupItem.h
+++ b/retroshare-gui/src/gui/feeds/GxsForumGroupItem.h
@@ -42,7 +42,7 @@ public:
 
 	bool setGroup(const RsGxsForumGroup &group);
 
-    virtual std::string uniqueIdentifier() const override { return "GxsForumGroupItem " + mGroup.mMeta.mGroupId.toStdString() ; }
+    uint64_t uniqueIdentifier() const override { return hash_64bits("GxsForumGroupItem " + groupId().toStdString()) ; }
 protected:
 	/* FeedItem */
 	virtual void doExpand(bool open);
diff --git a/retroshare-gui/src/gui/feeds/GxsForumMsgItem.cpp b/retroshare-gui/src/gui/feeds/GxsForumMsgItem.cpp
index 8e1dba4ea..0e691258c 100644
--- a/retroshare-gui/src/gui/feeds/GxsForumMsgItem.cpp
+++ b/retroshare-gui/src/gui/feeds/GxsForumMsgItem.cpp
@@ -43,6 +43,8 @@
 GxsForumMsgItem::GxsForumMsgItem(FeedHolder *feedHolder, uint32_t feedId, const RsGxsGroupId &groupId, const RsGxsMessageId &messageId, bool isHome, bool autoUpdate) :
     GxsFeedItem(feedHolder, feedId, groupId, messageId, isHome, rsGxsForums, autoUpdate)
 {
+    mMessage.mMeta.mMsgId = messageId;	// useful for uniqueIdentifier() before the post is actually loaded
+    mMessage.mMeta.mGroupId = groupId;
 	setup();
 
 	requestGroup();
diff --git a/retroshare-gui/src/gui/feeds/GxsForumMsgItem.h b/retroshare-gui/src/gui/feeds/GxsForumMsgItem.h
index 3563ed63a..be275aa07 100644
--- a/retroshare-gui/src/gui/feeds/GxsForumMsgItem.h
+++ b/retroshare-gui/src/gui/feeds/GxsForumMsgItem.h
@@ -43,7 +43,7 @@ public:
 	bool setGroup(const RsGxsForumGroup &group, bool doFill = true);
 	bool setMessage(const RsGxsForumMsg &msg, bool doFill = true);
 
-    std::string uniqueIdentifier() const override { return "GxsForumMsgItem " + mMessage.mMeta.mMsgId.toStdString() ; }
+    uint64_t uniqueIdentifier() const override { return hash_64bits("GxsForumMsgItem " + mMessage.mMeta.mMsgId.toStdString()) ; }
 protected:
 	/* FeedItem */
 	virtual void doExpand(bool open);
diff --git a/retroshare-gui/src/gui/feeds/MsgItem.h b/retroshare-gui/src/gui/feeds/MsgItem.h
index bcf9af30f..469f8cbb7 100644
--- a/retroshare-gui/src/gui/feeds/MsgItem.h
+++ b/retroshare-gui/src/gui/feeds/MsgItem.h
@@ -38,7 +38,7 @@ public:
 
 	void updateItemStatic();
 
-    virtual std::string uniqueIdentifier() const override { return "MsgItem " + mMsgId ; }
+    uint64_t uniqueIdentifier() const override { return hash_64bits("MsgItem " + mMsgId) ; }
 protected:
 	/* FeedItem */
 	virtual void doExpand(bool open);
diff --git a/retroshare-gui/src/gui/feeds/PeerItem.cpp b/retroshare-gui/src/gui/feeds/PeerItem.cpp
index 1d663a7c3..87d510e4b 100644
--- a/retroshare-gui/src/gui/feeds/PeerItem.cpp
+++ b/retroshare-gui/src/gui/feeds/PeerItem.cpp
@@ -67,9 +67,9 @@ PeerItem::PeerItem(FeedHolder *parent, uint32_t feedId, const RsPeerId &peerId,
     updateItem();
 }
 
-std::string PeerItem::uniqueIdentifier() const
+uint64_t PeerItem::uniqueIdentifier() const
 {
-    return "PeerItem " + mPeerId.toStdString() + " " + QString::number(mType).toStdString() ;
+    return hash_64bits("PeerItem " + mPeerId.toStdString() + " " + QString::number(mType).toStdString()) ;
 }
 
 void PeerItem::updateItemStatic()
diff --git a/retroshare-gui/src/gui/feeds/PeerItem.h b/retroshare-gui/src/gui/feeds/PeerItem.h
index ba108a92b..6e17fbae3 100644
--- a/retroshare-gui/src/gui/feeds/PeerItem.h
+++ b/retroshare-gui/src/gui/feeds/PeerItem.h
@@ -43,7 +43,7 @@ public:
 
 	void updateItemStatic();
 
-    std::string uniqueIdentifier() const override;
+    uint64_t uniqueIdentifier() const override;
 
 protected:
 	/* FeedItem */
diff --git a/retroshare-gui/src/gui/feeds/PostedGroupItem.h b/retroshare-gui/src/gui/feeds/PostedGroupItem.h
index f4ab14d39..999abf652 100644
--- a/retroshare-gui/src/gui/feeds/PostedGroupItem.h
+++ b/retroshare-gui/src/gui/feeds/PostedGroupItem.h
@@ -42,7 +42,7 @@ public:
 
 	bool setGroup(const RsPostedGroup &group);
 
-    virtual std::string uniqueIdentifier() const override { return "PostedGroupItem " + mGroup.mMeta.mGroupId.toStdString() ; }
+    uint64_t uniqueIdentifier() const override { return hash_64bits("PostedGroupItem " + groupId().toStdString()) ; }
 
 protected:
 	/* FeedItem */
diff --git a/retroshare-gui/src/gui/feeds/SecurityIpItem.cpp b/retroshare-gui/src/gui/feeds/SecurityIpItem.cpp
index 0ddc24fa1..40914fc7e 100644
--- a/retroshare-gui/src/gui/feeds/SecurityIpItem.cpp
+++ b/retroshare-gui/src/gui/feeds/SecurityIpItem.cpp
@@ -78,9 +78,9 @@ void SecurityIpItem::setup()
 	updateItem();
 }
 
-std::string SecurityIpItem::uniqueIdentifier() const
+uint64_t SecurityIpItem::uniqueIdentifier() const
 {
-    return "SecurityItem " + QString::number(mType).toStdString() + " " + mSslId.toStdString() + " " + mIpAddr + " " + mIpAddrReported ;
+    return hash_64bits("SecurityItem " + QString::number(mType).toStdString() + " " + mSslId.toStdString() + " " + mIpAddr + " " + mIpAddrReported) ;
 }
 
 void SecurityIpItem::updateItemStatic()
diff --git a/retroshare-gui/src/gui/feeds/SecurityIpItem.h b/retroshare-gui/src/gui/feeds/SecurityIpItem.h
index bba36a70b..d4648ab0a 100644
--- a/retroshare-gui/src/gui/feeds/SecurityIpItem.h
+++ b/retroshare-gui/src/gui/feeds/SecurityIpItem.h
@@ -43,7 +43,7 @@ public:
 
 	void updateItemStatic();
 
-    std::string uniqueIdentifier() const override;
+    uint64_t uniqueIdentifier() const override;
 
 protected:
 	/* FeedItem */
diff --git a/retroshare-gui/src/gui/feeds/SecurityItem.cpp b/retroshare-gui/src/gui/feeds/SecurityItem.cpp
index 751c0c0da..b5aa9d8a4 100644
--- a/retroshare-gui/src/gui/feeds/SecurityItem.cpp
+++ b/retroshare-gui/src/gui/feeds/SecurityItem.cpp
@@ -81,9 +81,9 @@ SecurityItem::SecurityItem(FeedHolder *parent, uint32_t feedId, const RsPgpId &g
 	updateItem();
 }
 
-std::string SecurityItem::uniqueIdentifier() const
+uint64_t SecurityItem::uniqueIdentifier() const
 {
-    return "SecurityItem " + QString::number(mType).toStdString() + " " + mSslId.toStdString();
+    return hash_64bits("SecurityItem " + QString::number(mType).toStdString() + " " + mSslId.toStdString());
 }
 
 void SecurityItem::updateItemStatic()
diff --git a/retroshare-gui/src/gui/feeds/SecurityItem.h b/retroshare-gui/src/gui/feeds/SecurityItem.h
index 99bb89673..1c9bbe054 100644
--- a/retroshare-gui/src/gui/feeds/SecurityItem.h
+++ b/retroshare-gui/src/gui/feeds/SecurityItem.h
@@ -42,7 +42,7 @@ public:
 
 	void updateItemStatic();
 
-    std::string uniqueIdentifier() const override;
+    uint64_t uniqueIdentifier() const override;
 
 protected:
 	/* FeedItem */