Bad boot from LiveCD 7.04

I'm trying to switch from XP to Ubuntu 7.04, recently downloaded as a CD-sized *.iso LiveCD. I played around with Ubuntu 6.06 a while back on my desktop, liked it a lot but ran up against some terminal stuff I didn't understand and dropped Linux for a while. I thought that, now that I'm better at terminal, I'd pick it up with the newest version. However, when I booted my Compaq Presario V6000 on the LiveCD, a problem developed. The main screen showed up fine, where Ubuntu asks what you want to do (i.e. Start or Install, Start in Safe Graphics, etc.,), and when I selected Start or Install Ubuntu, the standard text flew across my screen as I'm used to Linux doing. However, when it got to the end of that, about the time the login screen would normally show up, the screen went funny in a way that's hard to describe. First, it was grey with black horizontal bars across the screen. Then, a whiter stain spread up the screen from roughly the lower left center of the screen, leaving the black bars intact. When the screen was white but for the bars, vertical spikes of black developed from about the same area as the white stain. These proceeded, bringing with them a black spread that reminded my roommate of coral. Finally, the black bars expanded until the screen save for a postage stamp sized area at the upper right corner of the screen was black. That small area was a slightly lighter shade of black. I tried rebooting with Start Ubuntu with Safe Graphics Mode, and the same thing happened. I tried a number of things on the LiveCD, and they all ended up the same--an unresponsive computer with an almost black screen. However, when I booted off the hard drive, XP loaded perfectly. I looked around at various issues this could be caused by, but all of the ones I found were dealing with the nVidia cards on systems where Linux was installed on a hard drive. As I am booting from a LiveCD, that type of fix will not work for me, I think. I have an nVidia GeForce Go 6150, which appears in nVidia's supported cards list for the FreeBSD x86 driver. Any help on this would be greatly appreciated as XP is starting to drive me up the same wall I was at with my desktop when I turned to 6.06. Thanks!