diff -r 1721de2065dd glass/glass-mat-lib-gtk/src/com/sun/glass/ui/glass_gtkcompat.c
--- a/glass/glass-mat-lib-gtk/src/com/sun/glass/ui/glass_gtkcompat.c
+++ b/glass/glass-mat-lib-gtk/src/com/sun/glass/ui/glass_gtkcompat.c
@@ -116,7 +116,8 @@
     if (visual
             && gdk_display_supports_composite(default_display)
             && gdk_screen_is_composited(default_screen)) {
-        gtk_widget_set_visual(window, visual);
+        //NOTE: we use the XVisualID from the DeviceMap (see Application.java)
+        //gtk_widget_set_visual(window, visual);
         return TRUE;
     }
 
@@ -255,7 +256,8 @@
     if (colormap
             && gdk_display_supports_composite(default_display)
             && gdk_screen_is_composited(default_screen)) {
-        gtk_widget_set_colormap(window, colormap);
+        //NOTE: we use the XVisualID from the DeviceMap (see Application.java)
+        //gtk_widget_set_colormap(window, colormap);
         return TRUE;
     }