Re:COM Error

[kevin]

COM error!
I have test COM On wine.
Tonight,I wrote a test program
First,I called CoInitializeEx(NULL, COINIT_MULTITHREADED)...
Second,I called CoGetClassObject(rclsid, dwClsContext, NULL,IID_IClassFactory, (PVOID*)&pcf) and return "RPC_S_INVALID_STRING_BINDING", It means The string binding is invalid.
who can tell why??
Thanks
kevin