why an exception

[wes weston]

The following change fixes the problem:

def grab_set(self):
         """Set grab for this widget.

         A grab directs all events to this and descendant
         widgets in the application."""
         self.wait_visibility()  ###############added#####################3
         self.tk.call('grab', 'set', self._w)

This is in:
/usr/local/Python/lib/python2.3/lib-tk/Tkinter.py line 521

'tested only in the case listed previously.
wes