wxPython Linux -> Windows

I'm trying to get my wxPython application running under Windows 2000.
The application was developed under Ubuntu Dapper using Python 2.4.3.
Under Windows, I'm running Python 2.4.1. Both platforms are running
wxPython 2.8.7.1.

I've created a small panel, called dbNav. This panel provides 4
wx.BitmapButtons (first,previous,next,last) and wx.CheckBox (delete).
The BitmapButtons enable and disable as appropriate, i.e. if you are on
the first record, the first and previous buttons are disabled.

In the wx.Frame I am working on, there are results from four tables, and
each has it's own dbNav panel.

Under Linux, the dbNav panel buttons work as expected. Under Windows,
only the first dbNav panel seems to respond to mouse clicks. The other
three dbNav panel buttons enable and disable visually (bitmaps are
grayed out / not grayed out), but buttons that should, don't respond to
mouse clicks. Neither can you tab through them.

Any suggestions?

Mark