Huge CPU time on Vista. Annoying problem.

Hi everybody.

My application contains several kernel calls and everything worked fine on XP (280 GTX and 8800M GTX).
When i tried to port my application to Vista (9800 M GTX) - i faced a problem: all kernels work fine except one. But this one kernel uses too much CPU time:
gputime=[18861.793] cputime=[677435.313]

What can be the matter?

I use Vista, VS 2008, CUDA 2.1 and this version of driver: http://www.laptopvideo2go.com/drivers/vista/181.20. Videocard is 9800 M GTX.
(BTW in “Display properties” forceware 185.20 is displayed - also strange).

Did someone experienced similar problems?