I upgraded Xubuntu 12:04 to 12:10, and found it wouldn't boot any more! Just hung at the Xubuntu loading screen. It was odd, because I'm running it on a Dell Inspiron 1525, that came with Ubuntu pre-intalled, so I knew all my hardware was compatible. I'd also fun Xubuntu 12:10 from a live USB, to check it worked.
So, I did a fresh install instead. Found that to be sooo buggy that I reinstalled 12:04, just so I could get some work done. This is the first time I have ever had a problem with the upgrade process, and the first time I have ever had to resort to reinstalling a previous version. I've been using Ubuntu since Gutsy Gibbon in '07, and I even had the random freezing problems what, one or two years back.
Was rather disappointed, but as reinstalling 12:04 left me with no problems, I've not started any help threads on anything!