G'day "Cass" ,
I have a big fat article on controlling Task Panes available on
http://word.mvps.org. There are several solutions to your problem in
it.
Steve Hudson - Word Heretic
steve from wordheretic.com (Email replies require payment)
Without prejudice
Cass reckoned:
I was sent a document through email and every time I open it the mail merge
task pane opens also. How do I stop that from happening.