Here is my setup:
I7 3770K HD4000 + GTX580 Win7 x64
Driver installed 320.00/320.18 for the GTX580 or 314.22
Intel side 188.8.131.5232
When I develop for OpenCL on the HD4000 I just deactivate my GTX580 in the device manager and I can usually run any OpenCL application on the HD4000 (that is with the NVidia driver 314.22).
After updating to the 320.00 or 320.18, this doesn’t work anymore and any application using OpenCL is crashing (Ex GPU Caps Viewer OpenCL tests).
Since nothing has changed on my system between the tests except the NVidia driver It is difficult to put the blame on Intel :)
If NVidia is serious about supporting OpenCL, please try to avoid this kind of things (and put an OpenCL 1.2 driver out).
If not, then just remove the support and at least it will be clear and it should not interfere with the rest of the OpenCL devices.
In the mean time, I am back on 314.22.