Try setting your BIOS to defaults (removing the OC). I have an X3 720 and whenever my 4th core was unlocked OR I had it OC'd I had major crashing problems in both Dragons Age and Borderlands. I never had any problems with any of the other dozens of games I played previously with the exact same setup. Don't ask me why just those two games.
Nevermind your previous post just answered this.
Nevermind your previous post just answered this.