Since Adobe never supported Win XP 64 I would get rid of the operating system and move to Win 7 64. Changing video cards is not going to solve your problem and considering the sad stories concerning Matrox, I would guess that the only thing it would do for you is compound your problem. Generally system crashes with Adobe are caused by defective installations that require reinstalling your software after cleaning with the Adobe Cleanup script. But in this case you have the opportunity to start fresh with a virgin installation of Win 7
I appreciate the quick answer and am considering moving to Windows
7 (64). What is the sad story about Matrox? What is the best way to speed
up my rendering or processing without having to purchase another cpu? Thanx once again for your quick response. I render primarily to h.264
Matrox has a problem developing drivers timely and bug-free for Premiere. This is not always the case. Search these forums.
Now as a preview just for you I ran a benchmark with CS4 (I do not have CS3 running), I have run this portion of our beta version of PPBM5 previously many times with CS5 on an AVCHD H.264 sequence. With CS4 it took 173 seconds to encode with my very high end system with a hacked GTX 480, and with CS5 I get an average of 75 seconds for the same sequence, about 2.3 times faster.
I would suggest you just get a new disk drive and load Win 7 64 on it and keep your XP drive in a dual boot setup. That way you can load CS3 on the new disk and gradually transistion to the new OS.