diff --git a/source/app/ModulesHandle.cpp b/source/app/ModulesHandle.cpp
index 31ecc94..9236e85 100644
--- a/source/app/ModulesHandle.cpp
+++ b/source/app/ModulesHandle.cpp
@@ -81,8 +81,6 @@ SubWindowHandle* ModulesHandle::toggleSelectedModuleIf()
     {
       QString windowName;
       interfaceChild = new SubWindowHandle( m_pcParent );
-      pcSubWindow->setModuleSubWindow( interfaceChild );
-      pcSubWindow->enableModule( currModuleIf );
       windowName.append( pcSubWindow->userFriendlyCurrentFile() );
       windowName.append( " [" );
       windowName.append( currModuleIf->m_cModuleDef.m_pchModuleName );
@@ -93,12 +91,8 @@ SubWindowHandle* ModulesHandle::toggleSelectedModuleIf()
       currModuleIf->m_pcDisplaySubWindow = interfaceChild;
       currModuleIf->m_pcDisplaySubWindow->setModule( currModuleIf );
     }
-    else
-    {
-      pcSubWindow->enableModule( currModuleIf );
-      currModuleIf->m_pcDisplaySubWindow = pcSubWindow;
-    }
     currModuleIf->m_pcSubWindow = pcSubWindow;
+    pcSubWindow->enableModule( currModuleIf );
   }
   else
   {
@@ -122,7 +116,10 @@ PlaYUVerFrame* ModulesHandle::applyModuleIf( PlaYUVerModuleIf *pcCurrModuleIf )
   case MODULE_REQUIRES_THREE_FRAMES:
     break;
   }
-  pcCurrModuleIf->m_pcDisplaySubWindow->setCurrFrame( processedFrame );
+  if( pcCurrModuleIf->m_pcDisplaySubWindow )
+    pcCurrModuleIf->m_pcDisplaySubWindow->setCurrFrame( processedFrame );
+  else
+    pcCurrModuleIf->m_pcSubWindow->setCurrFrame( processedFrame );
   return processedFrame;
 }
 
diff --git a/source/app/PropertiesSidebar.cpp b/source/app/PropertiesSidebar.cpp
index 428cffa..bbc9514 100755
--- a/source/app/PropertiesSidebar.cpp
+++ b/source/app/PropertiesSidebar.cpp
@@ -549,7 +549,7 @@ Void FramePropertiesSideBar::stopHistogram()
 
 void FramePropertiesSideBar::slotUpdateDataHistogram()
 {
-  if( m_pcFrame && isVisible() )
+  if( m_pcFrame->isValid() && isVisible() )
   {
     // If a selection area is done in Image Editor and if the current
     // image is the same in Image Viewer, then compute too the histogram
diff --git a/source/app/SubWindowHandle.cpp b/source/app/SubWindowHandle.cpp
index 784b897..b3d28bb 100644
--- a/source/app/SubWindowHandle.cpp
+++ b/source/app/SubWindowHandle.cpp
@@ -56,7 +56,6 @@ SubWindowHandle::SubWindowHandle( QWidget * parent ) :
   //m_pCurrStream = new InputStream;
   m_pcCurrFrame = NULL;
   m_pcCurrentModule = NULL;
-  m_pcModuleSubWindow = NULL;
 
   m_cWindowName = QString( " " );
   m_bIsPlaying = false;
@@ -132,7 +131,6 @@ Void SubWindowHandle::disableModule()
   {
     PlaYUVerModuleIf* pcCurrentModule = m_pcCurrentModule;
     m_pcCurrentModule = NULL;
-    m_pcModuleSubWindow = NULL;
     ModulesHandle::destroyModuleIf( pcCurrentModule );
     refreshFrame();
   }
@@ -151,16 +149,12 @@ Void SubWindowHandle::refreshFrame()
     m_pcCurrFrame = m_pCurrStream->getCurrFrame();
     if( m_pcCurrentModule )
     {
-      if( m_pcModuleSubWindow )
-      {
-        m_pcModuleSubWindow->setCurrFrame( m_pcCurrentModule->process( m_pcCurrFrame ) );
-      }
-      else
-      {
-        m_pcCurrFrame = m_pcCurrentModule->process( m_pcCurrFrame );
-      }
+      ModulesHandle::applyModuleIf( m_pcCurrentModule );
+    }
+    else
+    {
+      m_cViewArea->setImage( m_pcCurrFrame );
     }
-    m_cViewArea->setImage( m_pcCurrFrame );
   }
 }
 
diff --git a/source/app/SubWindowHandle.h b/source/app/SubWindowHandle.h
index 1383e29..ccf85ba 100644
--- a/source/app/SubWindowHandle.h
+++ b/source/app/SubWindowHandle.h
@@ -51,7 +51,6 @@ private:
   ViewArea* m_cViewArea;
 
   PlaYUVerModuleIf* m_pcCurrentModule;
-  SubWindowHandle* m_pcModuleSubWindow;
 
   InputStream* m_pCurrStream;
   PlaYUVerFrame* m_pcCurrFrame;
@@ -103,10 +102,6 @@ public:
   {
     return m_cViewArea;
   }
-  Void setModuleSubWindow( SubWindowHandle* pcWindow )
-  {
-    m_pcModuleSubWindow = pcWindow;
-  }
   Void setModule( PlaYUVerModuleIf* pcCurrentModule )
   {
     m_pcCurrentModule = pcCurrentModule;
diff --git a/source/app/plaYUVerApp.cpp b/source/app/plaYUVerApp.cpp
index dec355e..5aacfce 100644
--- a/source/app/plaYUVerApp.cpp
+++ b/source/app/plaYUVerApp.cpp
@@ -239,6 +239,8 @@ void plaYUVerApp::selectModule( QAction *curr_action )
     interfaceChild->zoomToFit();
     interfaceChild->getViewArea()->setTool( m_appTool );
   }
+  if( activeSubWindow() )
+    m_pcCurrentSubWindow = activeSubWindow();
   updateFrameProperties();
   return;
 }