I'm not sure how this is happening, but my computer will freeze when the screensaver turns on. Or at least i think thats what is happening, because I'll leave the computer for 5-10 minutes, and when I get back, it will be frozen. This problem occurs randomly. If i press the power button, it turns off immediately like if it were frozen, and the HD access light is stuck on. I've looked in /var/log/messages and warn and I don't see anything. I'm running
SuSE 10.0-kernel 2.6.13-15.10 default.
Asus P4S8X-MX
P4 2.4
Nvidia FX5200 with nvidia's drivers.

[edit]
ok, it happened while I was actually using the computer. I heard my HD spin down, and then it spun back up. The HD light stayed on, and after 5 seconds, it froze. bad acpi?

First make sure it isn't your hardware.
The two most common reasons for a full system freeze are over-heating and broken memory sticks.

You also mentioned using NVidia.
Is this an AGP card?
After this system freeze, can you still move your mouse pointer?

Does it only freeze in X(the graphical part, press Ctrl-Alt-F3 to get in CLI mode and type "init 3" to kill X)?

i don't think its overheating, the sensors say cpu is about 39 C mb is 40. i bought the ram/cpu/motherboard maybe two months ago. the graphics card is an agp, i stole it from an older dell, but i can run games without problems.
the system dies completely, keyboard/mouse don't work, neither does ssh.

Does it also freeze if you boot in safe/rescue mode?

Their really exist many reasons that can do this(mostly faulty ram, a corrupted or bad hard drive(or filesystem), bad power supply , disk controllers, ...
Did ever had this problem with an other distro(or OS)?
You could try a live CD like Knoppix to see if it freezes as well. If this doesn't work either, it's probably your hard drive(bad sectors), your bios or a plain system bug.