Help Pleeeeaaasseee Help Fx5600 Q!

Hey, I posted earlier on. I just got a FX5600. Installed the newest drivers from NVidia but ever since I installed it I've been having trouble with various bits in the system. Media player and other music players incur serious crackling and any movement on screen disturbs the sound (is this an interrupt or input overlap?).

Some games (higher end ones), like ground control 2 and Rome:total war (I know it's only a demo) crash for no apparent reason. They start out working fine and then a minute or so into the game they crash . Before this there is little or no lag at all.

Can't find any drivers for the 5600 on the MSI site, don't know why. Am going to try the Unified driver from NVidia and see if that works.

1.2Ghz, 256MB Ram, GeForce FX5600, plenty of hard drive space free and onboard sound. system seems to be getting quite hot despite having two seperate fans, have removed side panel to keep it cool.

Please Please Pleas any suggestions
Ta!

Doc