Comment 64 for bug 551013

Same here, on a 64-bit system, fresh install (upgraded from 9.04 and then did fresh install to test if it solves the issue). No splash screen appears after GRUB selection. A long black screen, only during the late stages of which the hard drive can be heard doing anything.
Intel Core Two Duo
nVidia GeForce 8800 640MB (current version drivers installed)

After a relatively long wait (was not the case with 9.04 and previous versions), there are 5 dots with scrambled colours on screen followed by 3 "Ubuntu" logos appearing on screen with a few dots beneath them. This only lasts a second and then the logon screen appears.

Same phenomenon when shutting down (3 "Ubuntu" logos coloured weird and with blurred lettering pop up for a second).

I will give this proposed solution a try, providing it does not remove the proprietary drivers.