We are experiencing a very intermittent problem with a few users. When they dial in to retrieve their voicemails or to change their message, they can log into Unity but then get the message that the message store is not available. Other users are working fine on the same server and message store. I have run the permissions wizard with no luck. We're running Exchange 2003 and some of the mail servers are virtualized and some are not. The problem seems to happen on either type of server. Any suggestions?