Oblivion crashing

Hello, first timer here. Oblivion will run and then crash at random. "This program has encountered a problem and needs to close, sorry for the inconvenience." Have tried uninstalling and reinstalling, nothing changes. Have newest game patch and newest video card drivers. Have also tried lowering game graphics, still the crashing. ***!

Specs:
Antec True 380S - 24A on +12V rail
MSI K8N Neo4 (MS7125) socket 939
AMD Athlon 64 3200+, MMX, 3DNow, 2Ghz
1Gb RAM DDR SDRAM
ATI X800XL PCI-Express 256MB
WDC WD1600JD-00HBB0 149GB IDE
Windows XP Pro Build 5200 service pack 2
Directx 9.0c