I've checked wether usplash is the cause by deactivating usplash. is has definetly nothing to do with usplash. It only appears at Xorg startup or if you switch back to gdm. But I've also seen this bug on kubuntu with kdm.
-- Screen is distorted for a few seconds at X startup shutdown https://launchpad.net/bugs/53878 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
