Error: linkage specification is incompatible with previous "clCreateBuffer"...

I am trying to follow this tutorial to set up OpenCL to add two vectors, but I get this error message on clCreateBuffer:

Error: linkage specification is incompatible with previous “clCreateBuffer” declared at line 544 of “C:…\CUDA\v6.5\include\CL\cl.h”

// Returns the cl_mem object referencing the memory allocated on the device
cl_mem clCreateBuffer (cl_context context,   // The context where the memory will be allocated
          cl_mem_flags flags,
          size_t size,   // The size in bytes
          void *host_ptr,
          cl_int *errcode_ret);

I have CUDA version 6.5, and I ran another tutorial to blur an image, which worked fine. I am guessing maybe not all commands work, depending on what OpenCL drivers you have? I have trouble to understand if OpenCL code is supposed to work the same for all devices or not. I use visual studio 2010, C++ and CUDA 6.5 drivers on Windows 7 with Nvidia Geforce 525M.