cuGetMeminfo Fails

cuGetMeminfo method fails and returns totalMem=0 on my laptop, also mem alloc on GPU fails.
I am running cuda on quadro K2000m with Cuda Driver 5.0 and using 4.2 cuda toolkit.
Question 1:
is it exactly needed to use the same version driver and toolkit?
Ques 2:
some partners in my group can just use 4.2 and i don’t want to roll back my driver to the very old 301.XXX with the support of toolkit 4.2. i dont know whether there is a method to solve this.

Anyone can help? Many thanks.

Drivers are backwards compatible with older toolkits. I recently did some test runs with code compiled by CUDA 0.8 that ran fine on a CUDA 5.0 capability driver.

so, last night i have updated my toolkit version to 5.0 and it is the same as my driver version now.but the function alse fails.i wonder whether it is not supported well on quadro new kepler families.

What error code are you getting from the failed calls?