I am having a problem getting a C callback to correctly activate in a C# program after using a dllimport.

Here is the declaration of the C code in the C header:

Code:
typedef BOOL (CALLBACK *HII_PaymentAcceptedProc)(BYTE bSrcNode, BYTE bNumber, BYTE bType, WORD wValue);

HIIFAPI UINT WINAPI HII_PaymentAccepted(BYTE bDestNode, BYTE bNumber, BYTE bType, WORD wValue);
Then in the...