I've been using Unix/Linux for several years, but this is the first time I try to install/mantain a Linux box myself.
This is the problem: sometimes, X kind-of-forgets to draw a frame in new windows; sometimes it do not erase a window I close. But if I keep clicking, all X freezes. But everything else keeps working (clocks, load monitors, etc). Sometimes I can click Cntl-Alt-F1 and kill everything; sometimes not.
Often (again, not always) when it freezes the window frames turn into multicolored vertical lines.
The only regularity I have seen is that this happens when I open or close windows.
I have RedHat-7.0 and XFree86-4.0.2