The problem is unlikely to be your nVidia card - they are quite well supported and its unlikely that a problem with it would manifest itself in this exact way anyway.
I've had problems with Live CDs before, and I would recommend firstly trying the CD again if you haven't already.
If it still doesn't work, consider using a live USB instead. I've found them more reliable personally. The Ubuntu website has great instructions for creating them, and you will also find that the installation goes much more quickly if it does end up working.
If you don't have a USB stick, or really don't want to use one, try burning a different CD. Sometimes CDs don't burn properly and errors can result, so getting a different one and trying again might help.
Whilst there's a chance that the problem is with Ubuntu, and we will of course help you if they are, it's probably a good idea to eliminate these disk-related possibilities first as they are much more likely to be the cause.