Constant Crashing

So, this game has always crashed on me in mid-play. It used to happen primarily when doing a zone-in such as entering a building, instance, or using travel skills. Now it is happening at any time. At one point in time, I swapped from running the game with DirectX 10 to 9. I've lowered a lot of the graphic settings.

My setup is an AMD Athlon 7750 Dual-core Processor 2.70 GHz, 4 GB of RAM, Windows Vista 32 bit OS, and dual ATI Radeon HD 4870 X2 with cross-fire.

Any suggestions?

Edit to Add: I have made sure my display drivers are up to date.