Chalenge,
     I have a very similar system with same problem.
as8n32SLI  2GB ram, AMD 64 FX-60 2.6 Ghz.
2 BFG 7950GT but not in SLI.  I use up to 4 monitors.  So far just 1 mon in AH2. Win XP SP2.  Been using Nvidia driver 93.71 for a while seems good.  I always hated switching drivers as various games stop working then.  I have AVG virus center which I close down each time before I start AH2, not sure if I have to but I do.  Also try going to your OTHER firewall than Windows, 
Start, all programs, go up to NVidia Corporation, activearmour firewall and turn that puppy off and just use windows firewall. O, I added AH2 exe as an exception in the XP firewall also.  I also got rid of Nvidia tray icon, it was giving some odd transparancy error.   Of course the 4.42 mb AMD core optimizer patch and that windows KB896256.  I sure hope I did those correctly because I still get the clip board pages at an angle after it says stop moving the controls so fast.much. Hit H to get ur mouse back, but at this point its restart time.  Stable otherwise ie in training.