One of our workstations has begun to freeze or reset under some circunstances. We can reproduce this in both Linux and Windows so it's most likely a hardware issue.
The freezes most usually happen when using a compiler (C++, if you're curious). We believe this points to either faulty RAM or CPU overheating.
We cleaned CPU fans and replaced thermal paste. Temperature is now in the 30ºC range when idle and it does pick up when compiling (the last reading before the freeze is in the 40-50 range), but it also picks up under different circumstances which don't cause crashes. To put the temperatures in context, the processor is an Athlon XP 3500+ (which is inherently hot, I hear) and the motherboard is a K8N Neo4-F.
We tested different RAM chips in different banks and it seems to make no difference. We're currently doing an exhaustive memtest86 pass.
Any other likely causes for the freezes? At this point I fear the motherboard or the processor may be damaged. There were no hardware changes lately, but the power source did burn after a few automatic shutdowns due to heat, probably, and was replaced (the new one is more powerful so I don't think it may be the cause)