Had and issue (posted on Exchange Networks) with users on just one particular Exchange 2003 Mailbox Server where the users were getting Loading ......... displayed after login to OWA. Jay_Dale answered me back and I got suggested I look at KB910119. Did that and found the issue to be as the article said the Exchweb directory on this Backend Server and the Front Servers had a directory mismatch. Copied the directory missing from the Backend Mail server to the Front Ends and that resolved the Loading........ display issue and users were able to get into their email via OWA fine. Days later discovered that when the users try to reply to or send a new Email they get a message that Pops up saying "Forbidden" and they cannot send or Reply as a result.