This thread is around 1.5 months old with no acknowledgement from the developers on nVIDIA (Oh!!! This website is not officially endorsed by nVIDIA).
The answer you get is, try:
1) To disable CPU scaling (which I won't, that's important for me/my laptop to be cool)
2) Are you using Composite extension in X (Hell Yeah!!! That's why I bought an nVIDIA GPU for my laptop)
So let's not bug them more. The fellow developers might be very very very busy in sorting out issues for their drivers to be "Microsoft Windows Vista Ready".
They're not free to acknowledge and work on this bug. And we're not the only ones. There are many like us.
I'd rather suggest all of us to move to the Nouveau project and help the developers there and see if they can come up with a driver which can suffice our requirements.
I understand the points nVIDIA makes, that it can't open up its specs and also that it can't ship proper drivers for its Linux users and also that it can't acknowledge bugs from its users and also that it doesn't care how many users confirm the bug.
We now understand that you make "World Class GPUs".