Don't know if this was still the case with Office 2007, but there was a time when information about bullets was not saved with the document … all the .doc said was "use bullet n° 3 from the profile of the person who just opened this document on this PC", so if two users had set up different bullets you could guarantee one of the users would end up disappointed when they exchanged documents.

Try and see whether the 'problem' user has different bullet settings; other people on the forum will know a lot more about how to this (especially on an older version) than I do :-}