Excel 2007 Copy Worksheet Problem
 

I like to "move or copy" from a right click on the worksheet tab. My problem
is that all my open "books" do not show up on the drop-down menu. Always
worked fine until recently. Now I can still copy to a new book - but none of
my other open books show up so I can not copy or move to an existing book.
Is there any way to fix this?

Thanks