Problems with calls to "cudaEventElapsedTime"

So I’ve been using cudaEventElapsedTime to determine the framerate of an application I am writing. Under my development at work on a WindowXP 32 bit system (NVCC 3.0, Driver Version 197.68 32bit), I get valid results for framerate as I get reasonable values returned to the “*ms” variable which you pass as a parameter.

Recently however, I wanted to try the code on my home machine (Windows 7 x64, NVCC 3.1, Driver Version 258.96 x64 & 260.61 x64) as it has a faster processor, better video card, etc… But now I’m always getting a return of 0.0030 (milliseconds) from the call to cudaEventElapsedTime, which corresponds to a frame rate of about 300,000… The code is good, but not THAT good…

So I’m wondering if anyone else has had similar issues, and how they might have resolved them.