Ubuntu likes to freeze after a while (like an hour or two)

[Lord Xeb]

Sometimes when I leave my computer on and an application open (lets say abiword or sometimes nothing is open) and the screen saver kicks on and stays on for a little bit, my system will freeze. Sometimes it is default ubuntu peach, other times, it is black, but it is all the same. I have to restart my laptop sometimes because of it locks up. It use to never do this. What my be going on? Tell me what information I need to supply you and I will do it. Thanks

[stephenjbarr]

Boot up a live CD and do a memory test. Sometimes instability can be due to bad RAM. My system was becoming unstable, so I downloaded a stress testing package and used it to stress the machine (cpu, I/O, RAM). Afterwards, I removed one of the DIMMs and tested it again. Doing this, you can systematically test to see if one of your DIMMs is bad. Or, if you have only one DIMM, swap it for a different one and see if you gain stability.

-steve