Just intalled Ubuntu 12.04 from CD and install went with no problems. After rebooting, I get the initial purple screen and then a black screen with mouse pointer and a few stray pixels at the bottom left of screen.
Occasionally during the boot process, the purple screen comes back momentarily but then back to the black screen with the mouse pointer. When I finally give up and press the power button, the purple screen returns with the Shut Down box visible as it is shutting down.
Any ideas? I have tried adding nomodeset after quiet splash, but no change. Possibly not doing it correctly, since I am somewhat of a newbie to Linux.