grub menu scrambled?

I've noticed a couple of times recently when booting my FC6t2 x86_64 partition that instead of a normal grub menu screen with the light blue fedora image background and white text, I'll instead get a mess of scrambled lines (close to horizontal, but slanting down from left to right). I get to the FC6t2 menu from a chainloader entry in my master boot grub install. The master grub always displays fine. There is also a FC5 x86_64 partition I can chainload, and it's grub menu always displays fine as well. Did something about the way grub does video change in FC6t2? Anyone else seen this, or do I just have something funny with my particular machine going on? One grub boots, the system, the video goes back to normal. I have no problems with X.