I have an iPhone that is configured to sync with an SBS 2003 MS Exchange installation using MS ActiveSync. One day I started to notice that certain appointments would simply disappear from the iPhone, but would still be present in my Exchange Mailbox, OWA and Outlook.
I tried deleting and re-installing the MS Exchange configuration on my iPhone and it would still not sync all the appointments. Finally I checked the Application Logs on the server and found many instances of the following error:
"Unexpected Exchange mailbox Server error: Server: [SERVERAME] User: [USERNAME] HTTP status code: . Verify that the Exchange mailbox Server is working correctly.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp
I tried updating and restarting the server,and the problem persists.