Hi Codfish
sounds like we're getting close to a solution... Do you have the service pack installed? The reason I ask is because this contains several updates which a SLI set up benefit from. Plus Nvidia have just released some very good beta drivers, which again I think you may benefit from, get them here:
GeForce Release 174
The link is for the US version, don't forget if you live outside of the US to use the international version. I use these betas and they are very fast and many forum users are saying they're the best Nvidia has released so far.

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