Frozen Login Screen

I’ve been using Sun’s VirtualBox for about a month now on my Windows XP laptop and absolutely love it.  This morning, while trying to squeeze as much performance as I could out of it, I bumped the amount of my Ubuntu’s Virtual Machine’s Video Memory to 128MB and immediately noticed a problem:  when the VM would start up the screen was jumbled.  I bumped the setting back down to 64MB and things worked as they should.  If you are seeing something similar, try lowering the allotted video memory and see if that clears things up.