--- gimp-2.6.6/plug-ins/common/edge-dog.c	2008-09-25 20:00:53.000000000 +0200
+++ plug-ins/common/edge-dog.c	2009-07-08 12:37:43.000000000 +0200
@@ -997,6 +997,9 @@
 
   dog (image_id, preview_drawable, dogvals.inner, dogvals.outer, FALSE);
 
+  if (dogvals.invert)
+    preview_rgn.shadow = FALSE;
+
   gimp_pixel_rgn_get_rect (&preview_rgn, buffer,
                            0, 0, width, height);
 
