OpenCL and pyopencl error

I installed pyopencl on my new laptop, running Windows 7 x64.

I ran a demo from

http://enja.org/category/tutorial/advcl/

and I got a mysterious error:

pyopencl.LogicError: Context failed: invalid gl sharegroup reference khr

I installed the latest drivers, and worried a bit, but then I realized the problem was the Optimus device in my laptop. I went into the 3D settings in the NVIDIA control panel and changed the Global setting to use my high performing NVIDIA card instead of the Optimus built-in one.

That solved it for me. Now I can run the OpenCL/OpenGL interop demos.