diff --git a/gui_qt/basepreview.cpp b/gui_qt/basepreview.cpp
index c3009b4..2e7f18d 100644
--- a/gui_qt/basepreview.cpp
+++ b/gui_qt/basepreview.cpp
@@ -20,6 +20,7 @@ public:
         _ysize = ysize;
         
         _need_render = true;
+        _alive = true;
     }
     
     bool isFrom(BasePreview* preview)
@@ -27,6 +28,11 @@ public:
         return _preview == preview;
     }
     
+    void interrupt()
+    {
+        _alive = false;
+    }
+    
     void update()
     {
         _need_render = true;
@@ -48,6 +54,10 @@ public:
                 for (int y = 0; y < _ysize; y++)
                 {
                     QRgb col = pixbuf.pixel(x, y);
+                    if (!_alive)
+                    {
+                        return false;
+                    }
                     if (qAlpha(col) < 255)
                     {
                         QColor newcol = _preview->getPixelColor(_xstart + x, _ystart + y);
@@ -70,6 +80,7 @@ public:
     }
 private:
     BasePreview* _preview;
+    bool _alive;
     bool _need_render;
     int _xstart;
     int _ystart;
@@ -121,6 +132,22 @@ void PreviewDrawingManager::startThreads()
     }
 }
 
+void PreviewDrawingManager::stopThreads()
+{
+    for (int i = 0; i < _threads.size(); i++)
+    {
+        _threads.at(i)->askStop();
+    }
+    for (int i = 0; i < _chunks.size(); i++)
+    {
+        _chunks.at(i)->interrupt();
+    }
+    for (int i = 0; i < _threads.size(); i++)
+    {
+        _threads.at(i)->wait();
+    }
+}
+
 void PreviewDrawingManager::addChunk(PreviewChunk* chunk)
 {
     _lock.lock();
@@ -169,27 +196,19 @@ void PreviewDrawingManager::updateChunks(BasePreview* preview)
 void PreviewDrawingManager::performOneThreadJob()
 {
     PreviewChunk* chunk;
-    do
+
+    chunk = NULL;
+    _lock.lock();
+    if (!_updateQueue.isEmpty())
     {
-        chunk = NULL;
-        _lock.lock();
-        if (!_updateQueue.isEmpty())
-        {
-            chunk = _updateQueue.takeFirst();
-        }
-        _lock.unlock();
-        
-        if (chunk)
-        {
-            chunk->render();
-            PreviewDrawingThread::usleep(50000);
-        }
-        else
-        {
-            PreviewDrawingThread::usleep(50000);
-        }
-        
-    } while (true);
+        chunk = _updateQueue.takeFirst();
+    }
+    _lock.unlock();
+
+    if (chunk)
+    {
+        chunk->render();
+    }        
 }
 
 /*************** BasePreview ***************/
@@ -247,7 +266,7 @@ void BasePreview::initDrawers()
 
 void BasePreview::stopDrawers()
 {
-    //delete _drawing_manager;
+    _drawing_manager->stopThreads();
 }
 
 void BasePreview::updateData()
diff --git a/gui_qt/basepreview.h b/gui_qt/basepreview.h
index 844a1bd..bddcc16 100644
--- a/gui_qt/basepreview.h
+++ b/gui_qt/basepreview.h
@@ -108,6 +108,7 @@ class PreviewDrawingManager {
 public:
     PreviewDrawingManager();
     void startThreads();
+    void stopThreads();
     void addChunk(PreviewChunk* chunk);
     void removeChunks(BasePreview* preview);
     void updateChunks(BasePreview* preview);
diff --git a/gui_qt/mainwindow.cpp b/gui_qt/mainwindow.cpp
index ef82e23..833dd9a 100644
--- a/gui_qt/mainwindow.cpp
+++ b/gui_qt/mainwindow.cpp
@@ -60,6 +60,8 @@ int main(int argc, char** argv)
 
     result = app.exec();
 
+    BasePreview::stopDrawers();
+
     delete window;
 
     paysagesQuit();
diff --git a/i18n/paysages_fr.ts b/i18n/paysages_fr.ts
index 24915c6..235e797 100644
--- a/i18n/paysages_fr.ts
+++ b/i18n/paysages_fr.ts
@@ -709,139 +709,139 @@ Maintenir Ctrl : Plus rapide</translation>
 <context>
     <name>MainWindow</name>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="79"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="81"/>
         <source>Terrain</source>
         <translation>Terrain</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="83"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="85"/>
         <source>Textures</source>
         <translation>Textures</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="87"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="89"/>
         <source>Water</source>
         <translation>Eau</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="95"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="97"/>
         <source>Atmosphere</source>
         <translation>Atmosphère</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="121"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="123"/>
         <source>&amp;Load</source>
         <translation>&amp;Ouvrir</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="121"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="123"/>
         <source>Crtl+L</source>
         <translation>Ctrl+O</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="122"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="124"/>
         <source>&amp;Explore (F2)</source>
         <translation>&amp;Explorer (F2)</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="122"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="124"/>
         <source>F2</source>
         <translation>F2</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="123"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="125"/>
         <source>&amp;Quick
 render (F5)</source>
         <translation>&amp;Rendu
 rapide (F5)</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="123"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="125"/>
         <source>F5</source>
         <translation>F5</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="143"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="145"/>
         <source>Do you want to start a new scenery ? Any unsaved changes will be lost.</source>
         <translation>Voulez-vous commencer un nouveau paysage ? Les modifications non sauvegardées seront perdues.</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="143"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="145"/>
         <source>Paysages 3D - New scenery</source>
         <translation>Paysages 3D - Nouvelle scène</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="153"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="155"/>
         <source>Paysages 3D - Choose a file to save the scenery</source>
         <translation>Paysages 3D - Choisissez un fichier pour enregistrer la scène</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="153"/>
-        <location filename="../gui_qt/mainwindow.cpp" line="179"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="155"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="181"/>
         <source>Paysages 3D Scenery (*.p3d)</source>
         <translation>Scène Paysages 3D (*.p3d)</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="167"/>
-        <location filename="../gui_qt/mainwindow.cpp" line="170"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="169"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="172"/>
         <source>Paysages 3D - File saving error</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="167"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="169"/>
         <source>Can&apos;t write specified file : %1</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="170"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="172"/>
         <source>Unexpected error while saving file : %1</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="177"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="179"/>
         <source>Do you want to load a scenery from file ? Any unsaved changes will be lost.</source>
         <translation>Voulez-vous charger une scène ? Les modifications nons sauvegardées seront perdues.</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="177"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="179"/>
         <source>Paysages 3D - Load scenery</source>
         <translation>Paysages 3D - Charger une scène</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="179"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="181"/>
         <source>Paysages 3D - Choose a scenery file to load</source>
         <translation>Paysages 3D - Choisissez un fichier de scène à charger</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="189"/>
-        <location filename="../gui_qt/mainwindow.cpp" line="192"/>
-        <location filename="../gui_qt/mainwindow.cpp" line="195"/>
-        <location filename="../gui_qt/mainwindow.cpp" line="198"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="191"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="194"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="197"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="200"/>
         <source>Paysages 3D - File loading error</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="189"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="191"/>
         <source>Can&apos;t read specified file : %1</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="192"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="194"/>
         <source>This file doesn&apos;t look like a Paysages 3D file : %1</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="195"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="197"/>
         <source>This file was created with an incompatible Paysages 3D version : %1</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="198"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="200"/>
         <source>Unexpected error while loading file : %1</source>
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="206"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="208"/>
         <source>A 3D landscape editing and rendering software.
 
 Authors :
@@ -854,12 +854,12 @@ GLib - http://www.gtk.org/
         <translation type="unfinished"></translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="91"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="93"/>
         <source>Sky</source>
         <translation>Ciel</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="99"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="101"/>
         <source>Clouds</source>
         <translation>Nuages</translation>
     </message>
@@ -868,7 +868,7 @@ GLib - http://www.gtk.org/
         <translation type="obsolete">Eclairage</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="107"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="109"/>
         <source>Render</source>
         <translation>Rendu</translation>
     </message>
@@ -877,22 +877,22 @@ GLib - http://www.gtk.org/
         <translation type="obsolete">&amp;Scène</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="119"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="121"/>
         <source>&amp;New</source>
         <translation>&amp;Nouveau</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="119"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="121"/>
         <source>Crtl+N</source>
         <translation>Ctrl+N</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="120"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="122"/>
         <source>&amp;Save</source>
         <translation>&amp;Sauvegarder</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="120"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="122"/>
         <source>Crtl+S</source>
         <translation>Ctrl+S</translation>
     </message>
@@ -929,7 +929,7 @@ GLib - http://www.gtk.org/
         <translation type="obsolete">Ai&amp;de</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="124"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="126"/>
         <source>&amp;About</source>
         <translation>&amp;A propos</translation>
     </message>
@@ -950,7 +950,7 @@ GLib - http://www.gtk.org/
         <translation type="obsolete">Voulez-vous charger un paysage ? Les modifications nons sauvegardées seront perdues.</translation>
     </message>
     <message>
-        <location filename="../gui_qt/mainwindow.cpp" line="206"/>
+        <location filename="../gui_qt/mainwindow.cpp" line="208"/>
         <source>Paysages 3D</source>
         <translation>Paysages 3D</translation>
     </message>