Just wanted to say thank you for this tip! It's worked well for me, now it's semi useable!
FYI another tip I came across was running Aero mode and not basic mode, for some reason the GPU acceleration only comes on with Aero and not with basic mode! I can't figure this out and it is quite a pain though because fullscreen starts to choke when there's no more Aero shown.
Win 7 x64 Pro/4GB Gskill RAM/160GB Intel X25-M G2 SSD/Alfa USB wireless adapter/Logitech K400 HTPC keyboard