DLLNotFound

Hey all,
I have a c++ plugin which works so far as I can make one call to it.
When I call it a second time I get a DLLNotFound Exception.
Anybody ran also in this issue and has a clue how to fix that.
THX in advance

The method signature does not match, I guess. Exam carefully.

answer winner thx for your reply.
That is not the case, because if I change the call order it just always happens on the second call.
All calls work if I call them independently.