MAFoElffen over at the Ubuntu forums came up with a fix for the black screen some users get after upgrading to 11.10 on comps with Nvidia cards. This unfortunately happened to a notebook I maintain (Dell XPS M1530) while upgrading it from 11.04 to 11.10. The relevant thread can be found here.
Although I still like Ubuntu in general, these small, but extremely frustrating, problems are some of the things holding it back. It’s not totally their fault due to the way a lot of hardware manufacturers only create drivers for their stuff when they’re bored at work or something. But the typical end-user doesn’t care and they won’t have the determination, knowledge, and/or desire necessary to fix these kinds of things.