--- wmaker-0.92.0/src/wmspec.c	2005-05-15 18:41:09.000000000 +0200
+++ wmaker-0.92.0/src/wmspec.c	2006-12-15 23:32:09.000000000 +0100
@@ -1268,11 +1273,13 @@
         XFree(data);
     }
 
-    ChangeStackingLevel(wwin->frame->core, layer);
-    wwin->frame->flags.need_texture_change = 1;
-    wWindowConfigureBorders(wwin);
-    wFrameWindowPaint(wwin->frame);
-    wNETWMUpdateActions(wwin, False);
+    if (wwin->frame) {
+        ChangeStackingLevel(wwin->frame->core, layer);
+        wwin->frame->flags.need_texture_change = 1;
+        wWindowConfigureBorders(wwin);
+        wFrameWindowPaint(wwin->frame);
+        wNETWMUpdateActions(wwin, False);
+    }
 }