I just found a way to repeat a BadWindow error in xemacs 21.1. When I played with the beta a few months ago it occasionally showed the same behaviour, but I could not figure out how to repeat it at the time. Procedure: 1. Help-bubbles enabled (those small, yellow boxes). 2. Place the mouse cursor close to the lower edge of a toolbar button. 3. Wait for the help-bubble to appear, it must overlap with the frame below. 4. Now move the mouse cursor to the right and into the help-bubble. You immediately get one X error message on your xterm: xemacs: X Error of failed request: BadWindow (invalid Window parameter) Major opcode of failed request: 40 (X_TranslateCoords) Resource id in failed request: 0x800a7e Serial number of failed request: 2908929 Current serial number in output stream: 2908929 xemacs: X Error of failed request: BadWindow (invalid Window parameter) etc... xemacs: X Error of failed request: BadWindow (invalid Window parameter) etc... Enclosed gif with hand drawn mouse cursor illustrates above. Apologies if this is old news and has already been fixed. -- Manfred