System Event Viewer Error

Good afternoon,
I have only one user with this problem. User running WinXP Pro – logon authentication server = NT4.0 – mapped drives from login script point to data on a Win2K server (all service packs & updates installed)

When he tries to savea document via a mapped dirve, sometimes it will save, other times it will hang his system and not save.

In the Event Viewer (System), I noticed this error: “The server received an incorrectly formatted request from \\COMPUTER NAME.”

Does anyone know what this means?

Thx much….

Rod