Bug 42974 lists the problem for multiple video cards. Bug 66652 describes a screen corruption near the end of the usplash progress (no idea if its related, but some console reset script might bork everything near the end of boot)
-- Latest usplash leaves my consoles corrupted https://launchpad.net/bugs/63558 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
