I know, it's a bit off-topic, but it may be useful.
I had random freezes when using semi-intensive graphics, but
processor-intensive operations (e.g. big kernel compiles) were OK (so it
looked like a software problem). I've had a hard time finding where the
problem was.
The bug was a hardware bug: 3 capacitors were dying on my motherboard. I
bought 3 replacements (a bit bigger to be sure) and soldered them
myself. Now X 4.2.1 debs work flawlessly (Xinerama on TNT2 + R128).
Thanks to Mark Vojkovich for finding an helpful web page, and to those
who helped.
Xav
