Most people get crashes on fo3 tbh, try all of the fixes such as quadcore(think you've done that), 4gb enabler, ffdshow fix and get some of the stabilizing mods from Fallout Nexus mate.
Try looking through the mods thread where most of the fixes are discussed. And i would definitely recommend CASM, which creates an autosave every minute or 3, then you will not lose much progress
Try looking through the mods thread where most of the fixes are discussed. And i would definitely recommend CASM, which creates an autosave every minute or 3, then you will not lose much progress