You say you have a custom plug-in - is this something you created, or a
plug-in that somebody else created for you? If you wrote the plug-in, you
need to run Acrobat in the debugger and see where it crashes. If you are
not the author, you have to work with the developer to debug the problem.
Make sure that you release any resource you've acquired. Are you doing
anything in an "OnClose" callback? If so, check that code carefully (but
again, running Acrobat in the debugger should point you to where things go
wrong).
Karl Heinz Kremer
PDF Acrobatics Without a Net
PDF Software Development, Training and More...