Finally heeding the warnings that my version of Ubuntu was out of date, I upgraded my Thinkpad T42 laptop to Ubuntu 12.04 LTS.
Bad move. It seems the ATI Radeon Mobility 7500 video adapter which has been supported for many years is now no longer supported. My laptop is now infuriatingly slow and there’s apparently no cure except to reinstall an older, less-douchey version of Ubuntu.
Between this and Ubuntu’s dumping of the Gnome desktop I’ve about had enough of Ubuntu’s boneheaded design decisions. Looks like I’ll be taking a look at the latest Fedora. At least it’s a hometown Linux company (i.e. Red Hat).
Try Xubuntu 12.04 LTS before you give up. I’ve upgraded all 3 of our Linux boxes to Xubuntu 12.04 in the last week. My wife’s 6+ year old box had a kernel problem that caused the root directory to fill up with 40 GB of error messages, but that was easily fixed by a config file edit to turn off video memory paging, or something like that. The other two, neither if which is particularly modern, upgraded without a problem.
BTW, when I say upgrade I mean a clean install of the root directory. I have never had the Ubuntu upgrade process go smoothly. I assume you have /home mounted as a separate partition…