Upgrade to 12.10 brought me to a black screen. Holding down shift got me to the grub menu, which allowed me to boot the newest kernel in recovery mode. Selecting "Enable Networking" took me to a new screen, but apparently locked up. Control+C allowed me to log in with networking. I removed the fglrx drivers in 12.10, allowed me to boot with x.org drivers for my 2009 ATI graphics (780G motherboard )

At which point I needed the fglrx drivers to run my monitor in high resolution.

The good news: Easy to install legacy ATI drivers with this PPA here: