Hi,
After a few more research, I have the same error in each case, with your examples and with my own ones (with visual studio 2k5 and 2k8).
After the first interaction with the 8061 card, a message box appear with this message : “No WinUSB support on this computer”. And finaly crash during the loading of k8061_C.dll.
It is strange, because I suppose that the WInUSB msg do not appear from my code by certainly from the DLL, so why does it try to load it once more ?
.dll is already in the debug & release directory.
In my own programs, the error hapenning with two method : your example’s method and with the [DllImport "K8061_C.dll] methodName();
Thanks for reading.