If you are upgrading to Cisco Unity 8.0 and reinstalling software on the Cisco Unity server (for example, because you are replacing the server or upgrading to Windows Server 2003), you must use the Data Store 2000 disc that ships with Cisco Unity 8...
Have you tried to delete the user from Unity and re-import him from AD? Since just one user is affected i wouldn't try to troublshoot the entire system, if after that the user is still having issue you might try to backup the mailbox in Exchange usin...
Normally those errors show up when you experience either MWI issues or no access to voicemail for one or multiple users, if it is the case i would make sure that the main Unity accounts have right permissions and that your Unity server is pointing to...
