Well what I did for my Sawtooth was boot the Live CD, copy the config file it generated in RAM onto a flash drive. Then copied it in place on my Frugalware 1.3 partition. The Frugalware bootscreen looked like it was in 16 colors but other than that the desktop worked fine. (A little slow, because of the old ATI Rage Pro/whatever is in it.)

It tends to be frustrating sometimes, Xorg isn't necessarily dropping/depreciating hardware support, but their config generator isn't working properly for older cards. As I mentioned, all I had to do was swap config files and everything was fine. Didn't have to go install an older version of Xorg or anything.

Did a little researching on the Ubuntu forums:

http://ubuntuforums.org/showthread.php?t=1488649#6

Debian 5.04 works, after some doing. You get the same magenta screen on first startup but Debian has a trapdoor on the X server: if X doesn't start in time then init drops you into a command shell.
Which is very convenient, since you can then log in as root, run "Xorg -configure" and follow instructions. Move the new xorg.conf in place, restart, et voilà: a working albeit somewhat slow desktop.

On Ubuntu this doesn't work, apparently because Xorg can't find the nVidia drivers (you can get into a simple CLI shell via the installation disk).

Click to expand...

This is for Ubuntu 10.04, post #9 in the topic mentions you can install Ubuntu using the 8.04 alternate CD, then upgrade to 10.04 using the update manager. Do let us know if you try this route and your results. (Although I just looked at the next page, and someone mentioned they didn't have the option to upgrade. :?: )

Edit: Here's an interesting topic: Ubuntu 11.04 and 10.04 on iLamp iMac freezes on boot.

Maybe one of these config files will help you.