FF XI Crashing repeadedlyFollow

When I first got the game this never happend. Then it started happening, usually about once per day. I never really thought too much of it untill recently when it started to become more frequent. Here is the error I get when it crashes:

http://img159.imageshack.us/img159/20/errorpu0.png

My setup:

512mb ram
athlon 64 3000+ (for some reason, a few months after I built the computer it started saying I had a 3200+)

radeon 9600XT

Please help me, it rapid crashed 6 times in a row within seconds of starting today (btw if my exp party is reading this I apologise) .