6600GT CS:S Stuttering

[Entropy]

Heya guys, my friend just got a 6600GT and its really choppy in CS: Source. He installed the 66.93 drivers.

His system is:

AXP 2500+ @ 3200+
1GB DDR400
80Gig ATA133
MSI 6600GT @ 550/1050
420W Thermaltake PS

Any ideas? I heard valve released a patch for that stuttering problem but it didnt fix it.

 

[Patman]

Always update the drivers, i think my friend uses 71 something with his eVGA 6600gt, hammers out 85 fps full settings 6x/16x 1280x1024. Pretty extreme