Not sure this is your answer, but what you're reporting did happen to me. It
turned out to be a problem with the button bar to which I had assigned a
button that would pull down the addresses. If you did the same, my problem
was that the Outlook button bar was different than Word's, and because I was
using Word as the Outlook editor, they were inconsistent. I solved the
problem by not using Word as the editor. Sorry if I've missed the mark. By
the way, in later updates the problem disappeared.