This seems like it may be a continuation of bug 1951, which is marked RESOLVED. When I boot up, on my old thinkpad with a radeon mobility 7500 graphics card, I get these crazy-looking rainbow swirls. If I set nomodeset, the problem goes away and my issue is solved, since my card is too old to play around with wibbly wobbly graphics effects anyway, so I always turn them off. Here's what it looks like, by the way: http://i.imgur.com/O8k9kQb.jpg http://i.imgur.com/GgelkM1.jpg
forgot to add: I have radeon-firmware installed, too.
I didn't realize this would have such an impact. radeon removed anything but KMS modesetting recently: http://lists.x.org/archives/xorg-announce/2012-November/002093.html, so I am stuck with the hippy art, or I get no graphics acceleration at all. At least it's interesting-looking.
found the solution: I disabled the "splash" boot argument. This definitively solves the problem.
Status: NEW => RESOLVEDResolution: (none) => FIXED