Messenger SP1 running on Netware 5.1 server

I have a user who received the following error while removing a
contact in Messenger.

"The server has experienced a directory error. For more information
contact your system administrator."

The user can no longer authenticate and consistantly continues to
receive the same error message from any workstation on the network.
I have reset the password and sycronized the user object but the
situation remains the same.

Has anyone seen this and/or know of a possible fix?

Jason Powers