OK, i think there must be a problem in the deb packages of some sort. i just ran quake3 and i still have the same probs: erratic mouse movements erratic clicks on the mouse buttons and in quake a slower framerate (1/4 to 1/3 of normal). since Quake is not using qtlibs (as far as i know of), the problem should lie somewhere else, ... I am tempted to install the XFree86 4.0.3 from the archives to see if this solves the problem...
marc
