Marc,
I responded VIA email but I will also discuss this here.
Since you are using a C++ environment, there may be problems with calling these functions (though technically they should work). I am unable to replicate this issue in CVI (what this toolkit is made for) however, could you try to use the non-Ex version of this function? If this still does not work, please email me a small example of this behavior in a small project and I can try to see if we can locate the problem.
