[wxPython] Refresh in 2.3.1

My screen refreshing seems to behavor differently with my update to 2.3.1
from 2.3.0. It's drawing the original MDI panel sized and then redrawing
them to the full screen OnSize values I've defined. It didn't bother to
display the initial draw before.

I tried a new setting I noticed in Main.py which was
wxNO_FULL_REPAINT_ON_RESIZE, but that didn't do it.

Something in my old approach isn't supported in the new version. Anyone
experience it and found out what's changed?

Lorne White