diff --git a/TODO b/TODO
index 9a48b3c9c..a8cd37d2b 100644
--- a/TODO
+++ b/TODO
@@ -46,4 +46,5 @@
 - Allow to scan multiple directories
 - Fix all (or almost all) opened bugs in bug tracker
 - Fix sorting with Qt 4.3 - Reported to Trolltech, waiting for fix
-- update sorting when a new torrent is added
\ No newline at end of file
+- update sorting when a new torrent is added
+- properties: reload torrent only if priorities changed
\ No newline at end of file
diff --git a/src/GUI.cpp b/src/GUI.cpp
index cf66e88c8..22525430a 100644
--- a/src/GUI.cpp
+++ b/src/GUI.cpp
@@ -593,7 +593,7 @@ void GUI::restoreInDownloadList(torrent_handle h){
   // Adding torrent to download list
   DLListModel->insertRow(row);
   DLListModel->setData(DLListModel->index(row, NAME), QVariant(h.name().c_str()));
-  DLListModel->setData(DLListModel->index(row, SIZE), QVariant((qlonglong)torrentEffectiveSize(hash)));
+  DLListModel->setData(DLListModel->index(row, SIZE), QVariant((qlonglong)BTSession.torrentEffectiveSize(hash)));
   DLListModel->setData(DLListModel->index(row, DLSPEED), QVariant((double)0.));
   DLListModel->setData(DLListModel->index(row, UPSPEED), QVariant((double)0.));
   DLListModel->setData(DLListModel->index(row, SEEDSLEECH), QVariant("0/0"));
@@ -1057,18 +1057,6 @@ void GUI::on_actionDelete_triggered(){
   }
 }
 
-size_type GUI::torrentEffectiveSize(QString hash) const{
-  torrent_handle h = BTSession.getTorrentHandle(hash);
-  torrent_info t = h.get_torrent_info();
-  unsigned short nbFiles = t.num_files();
-  size_type effective_size = 0;
-  for(unsigned int i=0; i<nbFiles; ++i){
-    if(h.piece_priority(i) != 0)
-      effective_size += t.file_at(i).size;
-  }
-  return effective_size;
-}
-
 // Called when a torrent is added
 void GUI::torrentAdded(const QString& path, torrent_handle& h, bool fastResume){
   QString hash = QString(misc::toString(h.info_hash()).c_str());
@@ -1080,7 +1068,7 @@ void GUI::torrentAdded(const QString& path, torrent_handle& h, bool fastResume){
   // Adding torrent to download list
   DLListModel->insertRow(row);
   DLListModel->setData(DLListModel->index(row, NAME), QVariant(h.name().c_str()));
-  DLListModel->setData(DLListModel->index(row, SIZE), QVariant((qlonglong)torrentEffectiveSize(hash)));
+  DLListModel->setData(DLListModel->index(row, SIZE), QVariant((qlonglong)BTSession.torrentEffectiveSize(hash)));
   DLListModel->setData(DLListModel->index(row, DLSPEED), QVariant((double)0.));
   DLListModel->setData(DLListModel->index(row, UPSPEED), QVariant((double)0.));
   DLListModel->setData(DLListModel->index(row, SEEDSLEECH), QVariant("0/0"));
@@ -1182,7 +1170,7 @@ void GUI::showProperties(const QModelIndex &index){
 
 void GUI::updateFileSize(QString hash){
   int row = getRowFromHash(hash);
-  DLListModel->setData(DLListModel->index(row, SIZE), QVariant((qlonglong)torrentEffectiveSize(hash)));
+  DLListModel->setData(DLListModel->index(row, SIZE), QVariant((qlonglong)BTSession.torrentEffectiveSize(hash)));
 }
 
 // Set BT session configuration
diff --git a/src/GUI.h b/src/GUI.h
index 80cef8d1c..9a58114cd 100644
--- a/src/GUI.h
+++ b/src/GUI.h
@@ -131,7 +131,6 @@ class GUI : public QMainWindow, private Ui::MainWindow{
     void createTrayIcon();
     void addLogPeerBlocked(const QString&);
     // Torrent actions
-    size_type torrentEffectiveSize(QString hash) const;
     void showProperties(const QModelIndex &index);
     void on_actionTorrent_Properties_triggered();
     void on_actionPause_triggered();
diff --git a/src/bittorrent.cpp b/src/bittorrent.cpp
index 6f22fd1a1..127706b7a 100644
--- a/src/bittorrent.cpp
+++ b/src/bittorrent.cpp
@@ -372,6 +372,40 @@ bool bittorrent::hasFilteredFiles(const QString& fileHash) const{
   return false;
 }
 
+// get the size of the torrent without the filtered files
+size_type bittorrent::torrentEffectiveSize(QString hash) const{
+  torrent_handle h = getTorrentHandle(hash);
+  torrent_info t = h.get_torrent_info();
+  unsigned int nbFiles = t.num_files();
+  if(!h.is_valid()){
+    qDebug("/!\\ Error: Invalid handle");
+    return t.total_size();
+  }
+  QFile pieces_file(misc::qBittorrentPath()+"BT_backup"+QDir::separator()+hash+".priorities");
+  // Read saved file
+  if(!pieces_file.open(QIODevice::ReadOnly | QIODevice::Text)){
+    qDebug("* Error: Couldn't open priorities file");
+    return t.total_size();
+  }
+  QByteArray pieces_priorities = pieces_file.readAll();
+  pieces_file.close();
+  QList<QByteArray> pieces_priorities_list = pieces_priorities.split('\n');
+  if((unsigned int)pieces_priorities_list.size() != nbFiles+1){
+    std::cerr << "* Error: Corrupted priorities file\n";
+    return t.total_size();
+  }
+  size_type effective_size = 0;
+  for(unsigned int i=0; i<nbFiles; ++i){
+    int priority = pieces_priorities_list.at(i).toInt();
+    if( priority < 0 || priority > 7){
+      priority = 1;
+    }
+    if(priority)
+      effective_size += t.file_at(i).size;
+  }
+  return effective_size;
+}
+
 // Return DHT state
 bool bittorrent::isDHTEnabled() const{
   return DHTEnabled;
diff --git a/src/bittorrent.h b/src/bittorrent.h
index 3888dfc6c..3160aaef4 100644
--- a/src/bittorrent.h
+++ b/src/bittorrent.h
@@ -84,6 +84,7 @@ class bittorrent : public QObject{
     QStringList getTorrentsToPauseAfterChecking() const;
     QStringList getUncheckedTorrentsList() const;
     long getETA(QString hash) const;
+    size_type torrentEffectiveSize(QString hash) const;
 
   public slots:
     void addTorrent(const QString& path, bool fromScanDir = false, bool onStartup = false, const QString& from_url = QString());