Access violation, invalid device Pointer What i do wrong?

Hi,
I am new to CUDA. I want to solve the thomson Problem with the help of CUDA
but i have problems:
I get a access violation in the “global void computeForces(…)” function at “float3 pos = pos_in[index];”
If i comment out all the code in the “global void computeForces(…)” i get an error on Invalid Device Pointer in the function
“void computeParticle(…)” at “CUT_CHECK_ERROR(“Kernel execution failed”);”. If you can see i wrote this code with the help of the
nBody example and the template code.
Can somebody help me to solve these Problems and say what i do wrong?

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THX
Thomson.zip (270 KB)