So that's why that happened to me... so far just once, as I don't have DVD player set to open automatically
(handbrake -- then view later off HDD I prefer. Ads, warnings, previews, and even the main menus annoy the heck out of me. Just play the _movie_ please). Just, the movie.
FWIW I have had a problem with the open source Burn program failing verify on DVD (data) burns any time except for right after a reboot... so maybe small chance there's a RAM-free issue with the drive itself. (System burn folders work fine, any time, 4x or 8x).
I guess VLC is the only alternative for straight-off-the-disc viewing, eh? PowerDVD or whatever else are Windows only from what I know.
I don't like the even faint implications that these panics could cause hardware damage.
However, FWIW, the X3100 drivers I suspect have more problems than this. To wit, Quicktime sometimes plays movies with a flickering brightness, and sometimes also a green & purple single line of pixels at the bottom. MPEG-1 files seem best to cause this, but have had x264 ones do it when moving a playing movie to an external screen. Sometimes quitting the player and re-opening the movie fixes it. Same movies in VLC, no issues.
And, also, World of Warcraft ends up sometimes with some textures getting mapped from the wrong place. Like, black with green and blue lines shows up on the side of objects. Stuff that looks like an old snow-crash getting mapped somewhere, that sort of thing.
It could be WoW, but it never happened on my iBook G4, so I'm thinking either the x3100 graphics chipset has bugs, or, Leopard's driver is beta-release quality.