problem with PythonCard -> wxPython -> _core.py -> class point -> __getitem__

[It's me]

I've built a Python application using PythonCard 1.9 and Python 2.3 running
under Windows XP.   Everything works except that when I use the keyboard
instead of the mouse to do certain operations in a data entry field (like
Shift-Home), the
program stops at line 1014 of wx-2.5.3-msw.ansi\wx\_core.py.

    def __getitem__(self, index):
        try:
            x = self.Get()[index]
        except IndexError:
            raise IndexError, "tuple index %d out of range of %d"
%(index,len(self.Get()))
        return x

I downloaded the current version of wxPython (2.5.3.1) and tried again.
Same problem except that they've removed the exception handler and simply go
with:

    def __getitem__(self, index):        return self.Get()[index]

at line 1012.   The debugging shows that someone is calling this routine
repeatedly with index greater then the left of self.Get().   That's the best
I can do.

Any help?

(I can report to the wxPython list if nobody knows how to get around this)

Thanks,