cudaSafeCall Error when trying to follow "Verifying your system"

I have just installed Windows 7 x64 Ultimate (I figured the Vista forum is the best bet) on my PC it has 3x Tesla C1060s and a Geforce 8400 GS.
I’ve been following the “Verifying your System” on I’ve successfully completed the deviceQuery and bandwidthTest. But when I run “–benchmark --n=131072 --device=0” I recieve this error “cudaSafeCall() Runtime API error in fil<d:/devtools/SDK10/CUDA_2.3/SDK10/Computer/C/src/nbody/>, line 75 : unknown error.”

If anyone can help me with a fix it would be greatly appreciated.