I am running 11.04 Desktop 64bit on my Thinkpad X220 which is brand new. I ran Windows on it for a few days and that seemed to run fine. It's still on there on a separate partition.
Ubuntu installed OK, with no major issues except that my screen gets garbled at irregular intervals. The way in which it gets garbled is not consistent -- see example screens below -- and I have found no way to reproduce it.
It never happens straight after bootup, it seems to mostly occur after a day of work. I can keep working, everything responds like there is nothing wrong, except I can't see what I'm doing anymore. Needless to say this is hyper annoying. Before I send the laptop back to get it repaired or replaced, I would like to try and find out if this even a hardware problem or if it's traceable to Ubuntu. It does not seem to happen under Windows but then I rarely boot into Windows.