diff --git a/common/gal/opengl/opengl_compositor.cpp b/common/gal/opengl/opengl_compositor.cpp
index 621428e..1f196f0 100644
--- a/common/gal/opengl/opengl_compositor.cpp
+++ b/common/gal/opengl/opengl_compositor.cpp
@@ -174,7 +174,7 @@ unsigned int OPENGL_COMPOSITOR::CreateBuffer()
         return 0;
     }
 
-    ClearBuffer();
+    // ClearBuffer();
 
     // Return to direct rendering (we were asked only to create a buffer, not switch to one)
     glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, DIRECT_RENDERING );
diff --git a/common/gal/opengl/opengl_gal.cpp b/common/gal/opengl/opengl_gal.cpp
index 4668145..5534ffe 100644
--- a/common/gal/opengl/opengl_gal.cpp
+++ b/common/gal/opengl/opengl_gal.cpp
@@ -984,6 +984,9 @@ OPENGL_GAL::OPENGL_TEST::OPENGL_TEST( wxDialog* aParent, OPENGL_GAL* aGal ) :
 
 void OPENGL_GAL::OPENGL_TEST::Render( wxPaintEvent& WXUNUSED( aEvent ) )
 {
+    if( !m_parent->IsShown() )
+        return;
+
     if( !m_tested )
     {
         m_result = true;    // Assume everything is fine, until proven otherwise
diff --git a/include/gal/opengl/opengl_gal.h b/include/gal/opengl/opengl_gal.h
index bfaafed..8af1bea 100644
--- a/include/gal/opengl/opengl_gal.h
+++ b/include/gal/opengl/opengl_gal.h
@@ -363,6 +363,7 @@ private:
     public:
         OPENGL_TEST( wxDialog* aParent, OPENGL_GAL* aGal );
         void Render( wxPaintEvent& aEvent );
+
         inline bool IsTested() const { return m_tested; }
         inline bool IsOk() const { return m_result && m_tested; }
         inline std::string GetError() const { return m_error; }