Yep, seems the corruption is gone with latest kernel and X bits. I just rebooted again. I noticed a couple oddities but no corruption:
On what I think is the plymouth splash screen, I see what looks to be parts of shadows from some letters. I'm guessing that since I never see the logo during boot, this is just plymouth failing during rendering or something. Then later there's a black flicker when X kicks in, and for a very brief moment I see what looks like a sliced up incorrectly-tiled image of the desktop, but it clears and the right desktop image shows. But no corruption or other stuff shown on the screen that looks like it'd be problematic, as before. So I'm going to close the bug as fixed. ** Changed in: xserver-xorg-video-ati (Ubuntu) Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in ubuntu. https://bugs.launchpad.net/bugs/716596 Title: Corruption during boot-up _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp