Staff inbox number missing / incorrect

We have a staff member who only shows 1 in the 'inbox' on the Home page list of unresolved tickets by owner. However, this person had 25+ assigned to them. User claims they can't see them in the 'My Tickets' box either. Any ideas of where to look or what might be causing this?

Thanks in advance. I've received so much info and help just by reading the forums. Keep up the good work!

Anna