Operation Failed

Hi All

Have a Windows 2000 SBS with all updates for Windows, Office, and Exchange. Have Norton Crp 8.1 for AV,have 20 users, but have one user that recieves a “Operation Failed” in OOutlook 2000 send and receive. He Terminals in and works great then all of a sudden the error pops up. I can reboot the server and it starts working again. I have blown his account away, recreated it. Changed the name, username, gave him full rights, I know I should not, give him that , but wanted to see if it was a permission problem. There are no event logs. I have tried Microsoft article 223468. and anything else I could find. no other user has this problem. I have watched his email and nothing coming in, or going out seems to be the problem. So Help????