Kev I said document compatibility. Most of the machines in our environment are running 2007 or 2010 now, but we still have a few running 2003, and even with the docx compat pack you still get weird issues from time to time. I was just speculating anyway, sounds like your bosses just have "ooh shiny" syndrome.
In defense of newer versions of Office, everyone I know who actually uses Office apps for a living loves 2007 and 2010. I usually just use Notepad
