Problem with installing CUDA4.0 on my new Quadro 600 card

I downloaded the driver from the official website and installed them according to the instruction correctly. However, after I successfully compiled all programs in SDK and ran the deviceQuery, it showed errors like below:

CUDA Device Query (Runtime API) version (CUDART static linking)

cudaGetDeviceCount returned 38
→ no CUDA-capable device is detected

Here is some detail about my case
Card: Quadro 600
NVRM version: NVIDIA UNIX x86_64 Kernel Module 270.41.19 Mon May 16 23:32:08 PDT 2011
GCC version: gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5)

still hampered by this problem here…