> Eek!
>
> I am seeing exactly the same problem with Squeak 4.5, and it is happening
> with both Cog and the standard interpreter VM.
>
> I am using a laptop running Ubuntu. It's hard to believe that nobody would
> have noticed this before, so maybe it is specific to the hardware or graphics
> drivers.

I'm not having any problems invoking full-screen on and off in 4.5
under Ubuntu..