New Message number not updating on Public Folder

We are using a network fax software, GFI Faxmaker, to route all incoming faxes to a Public Folder in Exchange.  Everyone looks to that Public Folder in Outlook 2007.  The way they tell if new faxes are there is to look at the number in parentheses next to the name of the Public Folder.  Well that number has stopped updating for some reason.  there are new messages/faxes in the Public Folder but the number never increases.  I don't know what changed, it just stopped one day.  We are using Exchange 2010 on a SBS 2011 Standard server.  Can anyone point me where to look?

thanks