Also, you should get VC-1 acceleration with PowerDVD. It's Nvidia cards that don't accelerate VC-1, so something is up there. I'd look into that some more.
yes, maybe the driver version as I am using 7.12 atm and the review below does indeed indicate vc-1 acceleration with 7.7's
http://enthusiast.hardocp.com/article.html?art=MTM2MCwxMSwsaGVudGh1c2lhc3Q=