It's a bug! It's a bug!
I was feeling good, congratulating myself for finding a bug in wxPython's wxListBox control, but slightly miffed that the developers could let something that basic get through unit testing.
Then it hit me - no, I was doing something wrong. And I looked at the documentation, not for wxPython, but for Python itself - specifically the range keyword. And lo and behold, I was using range wrong.
Oops. At least I didn't embarrass myself publicly.
Oh, wait a minute. This is a public weblog entry...