This is two fold, it workaround qt problem not invalidating frame
when it's draw 'inverse'. And two, by normalizing the frame rect
InvalidateFrame really work as it should and invalidates only
one pixel for each frame side.
Fixes monochrome bitmaps under QT which should have 2 colors
or else it will trigger assertions if QT is compiled with
Debug Info.

This is a change from uncommited code to svn,