I have tried (and failed) to install Ubuntu 12.10 on a legacy HP/Compaq workstation (an Evo PRO). This did not surprise me, I'd guessed at a 30:70 success:fail ratio and was right. The issue is running Compiz into a generic driver, and on into legacy firmware. I'd done by best, the firmware revision of the box was the latest, but this was released around the XP/Vista transition.
The feeling is that 12.10 is developed around new graphics features, and simply does not want to know about legacy display adapters. if this is so, then frankly I am on-side and support this position. My solution was to do what I'm supposed to do and use 12.04.
Its a pity that !2.10 has no 2G or legacy support, but understandable none the less. Should however this be implicit on the tin?
Regards and thanks / Ed