After months with Ubuntu, I upgraded to Breezy. The usual teething problems was experienced.
The video was doing fine, games was playing OK etc. Then something went wrong and my games became jumpy. Running a simple app like "glxgears" and "top" shows 99.7% of cpu resources is used by Xorg. There is a very long thread on Ubuntuforums coming all the way from Warty about this problem, but so far nothing was resolved. The first posters thought it was their video card or their xorg.conf file. As the post grow longer it became clear that it is hardware independant as well as GUI independent. Some posters solved their problem by moving from Gnome to KDE or even XFC. But that was very few indeed. The bugzilla offer no helpfull insights either. So far the only known fix is to remove Ubuntu and do a fresh install. That's worse than WIndows!!!
Maybe the answer lurks on this forum?!!!