Power saving?
 

Using mandrake 10, my computer freezes quite often. If I leave my computer for a few hours, the monitor goes blank (power savings i assume). When I come back, the computer will almost alwass be stuck with the black screen. I turned off power saving via the Configure your Desktop button on the menu, and it sort of helped. Now it occasionally will work, however it still freezes more often then not. The only way to get it working after it freezes is by restarting. Does anyone know how to fix it?

Check system temperature and dust out your computer with compressed air.

System temperature is fine (about 30 degrees celsius). Any part in particular I should dust?

maybe ur linux system didn't detect the temp. sensor on your mobo correctly.
try install lmsensor or something.

My case has a lcd screen that I can use to view the temperatures... I haven used any temperature sensors from within the operating system.

Download memtest86 and boot into it. memtest86 checks the integirty of your system memory. It can take a few hours to days for memtest86 to be done.

Temperature sensors in computers and electronics just shows an estimate. In more extreme professional amplifiers uses three temperature sensors for each output device (transistor, MOSFET, or L-MOSFET) to get a more accurate reading of the temperature and to make sure the output devices are running at safe temperatures. I'm not saying to go that extreme on temperature sensors, but there are ways to get more accurate temperature readings. One way is to increase the temperature shown to certain degrees depending where the sensors are. Second way, to find the a formula for PCB and processors to compensate the temperature readings. From either these ways they will give accurate temperature reading. Your system could be at 46 degrees C or 52 degrees C. If you have set agreesive timings for memory (aka overclocking) or you increase the AGP level to 4X or 8X, your system will become un-reliable. Activating the the fail-safe in the BIOS will make it more reliable. Then push the settings a little bit a time until it is close to what you have. Linux uses every last drop of performance of your system than what Windows does. Windows rarely uses all your computer's performance.

Using either diodes or transistors are better than thermistor sensors. Diodes and transistors are more linear with temperature than thermistor sensors.

Dust everywhere using compressed air. Never use a vacuum cleaner in the computer.