Thanks for having reported this bug and helping in making Ubuntu better and sorry for having your report unanswered for so long.
It seems that was caused the error you observed is described in the following line of the file "main.log" that apport attached to the report: 2012-10-02 20:03:12,094 DEBUG nvidiaUpdate() 2012-10-02 20:03:14,092 ERROR NvidiaDetection returned a error: invalid literal for int() with base 10: 'experimental-304' Do you remember if you had any special nvidia driver installed when you did the upgrade or you were just using the ones provided by Ubuntu? ** Changed in: ubuntu-release-upgrader (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1060757 Title: Nvidia driver removed on upgrade -> Unity won't work To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1060757/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs