Comment 73 for bug 572521

I have a Dell Inspiron 1501 that has the same problem under 10.04 and under 10.10.

Two things "fix" the problem for me under 10.10:

Once the machine is fully up and running, presumably at the login screen but with the vertical bars / stripy pajama effect, if I suspend and resume, the resume comes back with a clean screen at 1280x800.

Also, there is a thread in the forums (sorry I don't have the topic to hand) that suggests putting "nomodeset" in the grub boot parameters; for me so far this ensures the machine comes up with a clean screen at 1280x800.

I hope this helps!