Index: /trunk/src/VBox/Additions/WINNT/Graphics/Wine/wined3d/shader.c
===================================================================
--- /trunk/src/VBox/Additions/WINNT/Graphics/Wine/wined3d/shader.c	(revision 43338)
+++ /trunk/src/VBox/Additions/WINNT/Graphics/Wine/wined3d/shader.c	(revision 43339)
@@ -2333,5 +2333,14 @@
     shader->parent = parent;
     shader->parent_ops = parent_ops;
-    list_add_head(&device->shaders, &shader->shader_list_entry);
+#ifdef DEBUG
+    {
+        IWineD3DBaseShaderImpl *tstShader;
+        LIST_FOR_EACH_ENTRY(tstShader, &device->shaders, IWineD3DBaseShaderImpl, baseShader.shader_list_entry) {
+            if (&tstShader->baseShader == shader)
+                return;
+        }
+        ERR("shader not in list!");
+    }
+#endif
 }