diff --git a/lib/native/windows-64/jawtrenderer.dll b/lib/native/windows-64/jawtrenderer.dll
index 79f2f7abe..9fa486a4c 100755
Binary files a/lib/native/windows-64/jawtrenderer.dll and b/lib/native/windows-64/jawtrenderer.dll differ
diff --git a/lib/native/windows/jawtrenderer.dll b/lib/native/windows/jawtrenderer.dll
index 77150dec1..6163f058f 100644
Binary files a/lib/native/windows/jawtrenderer.dll and b/lib/native/windows/jawtrenderer.dll differ
diff --git a/src/native/jawtrenderer/JAWTRenderer_Windows.cpp b/src/native/jawtrenderer/JAWTRenderer_Windows.cpp
index 68fd81c6b..52c3354e2 100644
--- a/src/native/jawtrenderer/JAWTRenderer_Windows.cpp
+++ b/src/native/jawtrenderer/JAWTRenderer_Windows.cpp
@@ -95,10 +95,10 @@ jboolean JAWTRenderer_paint
 
     if(!blitter->device->validate())
     {
-        blitter->lost = true;
-        return JNI_TRUE;
+      blitter->lost = true;
+      return JNI_TRUE;
     }
-
+    
     blitter->device->render(blitter->surface);
     return JNI_TRUE;
 }
@@ -119,6 +119,9 @@ jboolean JAWTRenderer_process
     if(!blitter->device || blitter->width != width || blitter->height != height
             || blitter->lost)
     {
+        D3DSurface* oldSurface = NULL;
+        D3DDevice* oldDevice = NULL;
+
         blitter->lost = false;
 
         /* size has changed, recreate our device and surface */
@@ -134,6 +137,11 @@ jboolean JAWTRenderer_process
             blitter->device = NULL;
         }
 
+        if(blitter->hwnd == NULL)
+        {
+            return JNI_TRUE;
+        }
+
         blitter->device = blitter->d3d->createDevice(blitter->hwnd, width,
                 height);
 
@@ -141,6 +149,7 @@ jboolean JAWTRenderer_process
         {
             /* device creation failed */
 
+            blitter->surface = NULL;
             /* maybe we go fullscreen and/or hwnd of the window has changed
              * so we return true to force native method to be called and so
              * update blitter->hwnd for the next call
diff --git a/src/native/jawtrenderer/windows/d3d_device.cpp b/src/native/jawtrenderer/windows/d3d_device.cpp
index 16c7c4225..73e3015c2 100644
--- a/src/native/jawtrenderer/windows/d3d_device.cpp
+++ b/src/native/jawtrenderer/windows/d3d_device.cpp
@@ -72,7 +72,7 @@ D3DDevice::~D3DDevice()
 {
     if(m_backSurface)
     {
-        m_backSurface->Release();
+        //m_backSurface->Release();
     }
 
     if(m_device)
diff --git a/src/net/java/sip/communicator/impl/neomedia/jmfext/media/renderer/video/JAWTRenderer.java b/src/net/java/sip/communicator/impl/neomedia/jmfext/media/renderer/video/JAWTRenderer.java
index d3394b125..3d563de58 100644
--- a/src/net/java/sip/communicator/impl/neomedia/jmfext/media/renderer/video/JAWTRenderer.java
+++ b/src/net/java/sip/communicator/impl/neomedia/jmfext/media/renderer/video/JAWTRenderer.java
@@ -354,12 +354,16 @@ public synchronized int process(Buffer buffer)
             }
 
             Component component = getComponent();
-            boolean repaint
-                = process(
+            boolean repaint = false;
+
+            synchronized(this)
+            {
+               repaint = process(
                     handle,
                     component,
                     (int[]) buffer.getData(), buffer.getOffset(), bufferLength,
                     size.width, size.height);
+            }
 
             if (repaint)
                 component.repaint();
diff --git a/src/net/java/sip/communicator/impl/neomedia/videoflip/VideoFlipEffect.java b/src/net/java/sip/communicator/impl/neomedia/videoflip/VideoFlipEffect.java
index 5142ec143..48934c20f 100644
--- a/src/net/java/sip/communicator/impl/neomedia/videoflip/VideoFlipEffect.java
+++ b/src/net/java/sip/communicator/impl/neomedia/videoflip/VideoFlipEffect.java
@@ -116,7 +116,7 @@ public Format[] getSupportedOutputFormats(Format input)
 
         return new Format[]
         {
-                (Format)input.clone(),
+            (Format)input.clone(),
         };
     }
 
@@ -150,7 +150,7 @@ public Format setOutputFormat(Format format)
      * @throws ResourceUnavailableException If all of the required resources
      * cannot be acquired.
      */
-    public void open() throws ResourceUnavailableException
+    public synchronized void open() throws ResourceUnavailableException
     {
         graph = FFmpeg.avfilter_alloc_filtergraph();
         inputstream = FFmpeg.avfilter_alloc_inputstream();
@@ -160,7 +160,7 @@ public void open() throws ResourceUnavailableException
     /**
      * Closes this effect.
      */
-    public void close()
+    public synchronized void close()
     {
         if(graph != 0)
         {
@@ -202,7 +202,7 @@ public String getName()
      * @return <tt>BUFFER_PROCESSED_OK</tt> if the processing is successful.
      * @see PlugIn
      */
-    public int process(Buffer inputBuffer, Buffer outputBuffer)
+    public synchronized int process(Buffer inputBuffer, Buffer outputBuffer)
     {
         int ret = 0;