Rome Total War : Problem with Freezing

When playing Rome total war, I'm experiencing pauses in the game that last from 2 to 10 seconds. Additionally I'm seeing blue 'flashes' in the terrain and shadows that sort of flicker and dance.

I don't have any graphics issues in other games that I play. Planetside is fine. Knights of the Old Republic runs fine. I just got this computer a week ago so I havn't had a ton of time to game with it and check its compatibility with a ton of games but so far things seem ok.

I updated my drivers from the nvidia site. I updated the drivers for the onboard sound from MSI's site, I updated the mobo drivers from the MSI site. I installed DirectX 9.0.0c. I accept the graphics options suggested by the game, I even lower them. I still get these pauses. Any ideas why?

Here are my system specs:

AMD Athlon 64 3200+
MSI K8N Neo Platinum
Corsair 1GB 3200 CL 2.5
Sonly 1.44MB Floppy
LG GSA4120BB DVD +/- RW
Seagate 200GB SATA
BFG GeForce 6800 GT
Antec Sonata Mid Tower Case, 380W PSU
Windows XP Home