Simon,

I just created two MDI forms with some VFP baseclass controls dropped on them, no code anywhere in the form and ran them both, maximized one of them and switched between them using the Windows menu item there was no problem with the way either one painted. Can you run a similar test?

I'm running on a Dell Inspiron 7000, RAGE LT PRO AGP 2X video.

>I have spent considerable time checking the LockScreen value it always says .False. You can query the form while in the jumbled state and the Lockscreen value says False. However, if you try oForm.Draw to force a repaint of the screen nothing happens. If I drag another form over top of the jumbled form it will repaint correctly as it does when I change the Windowstate.
>
>I do not see how lockscreen could explain why this happens only when the forms are maximized.