What we observed in our work with OCCT and graphics drivers (NVIDIA mostly) is that the application behaves differently depending on the settings/profile we use.
For example, until recently I had had a driver from December 2012 for my Quadro 1000M. In an OCCT application, which performs motion simulation I observed very high memory consumption and slowdown during the simulation was running (with opened local context). The memory was freed after returning to neutral point. No problem on my colleagues' PCs. But we had some customers who reported similar problem.
Trying to solve the issue I just switched the settings from "3D OpenGL Stereo" to "3D App - Visual Simulation". The problem was gone - no excessive memory consumtion during the simulation! Then I updated my graphics driver and switched back to the "3D OpenGL Stereo" profile. Everything works fine too!
Apparently, the problem was the implementation of the graphics driver. We also had similar issues in the past on various NVIDIAs with different symptoms (including crashes).
My question is: has anyone faced similar problem? Do you have any idea how to test the graphics driver if it is OCCT compatible or to find out which settings should be used to get maximum performance / avoid problems?