1) Do you have a release or debug version?
2) Is it a model or a UI plug-in.
3) If UI, there are menudefs in your fr file which determine where the menu item (the key to call you plug-ins dialog or panel).
4) Did you include the file "SDKPlugInEntrypoint.cpp" or a similar one in your plug-in?
Hope one of these points help. If you can acquire a debug version, it should spell the error for you during start cycle.