I "upgraded" to the pre-release version of Ubuntu Jaunty. Unfortunately for me, my laptop, which runs the Intel Graphics Media Accelerator 950, became dog slow on graphics (more like my dog, and not like a fast greyhound). The solution I found online was:
sudo aptitude purge xserver-xorg-video-i740
Although this seems to be totally unrelated to my problem, the graphics got a lot more responsive. I still think it's a bit slow, but at least I'm past the initial hurdle.
For this and many other reasons, I'm still suspicious that Ubuntu is ready for the general user, unless it's preinstalled on a machine.