How to resolve Event ID 64004 on Windows 2000 Server

I have recently started to receive numerous errors in the Event Viewer on one of our servers:

Event Type: Information
Event Source: Windows File Protection
Event Category: None
Event ID: 64004
Date: 4/23/09
Time: 12:26:53 PM
User: N/A
Computer: SELTECH2
Description:
The protected system file winmgmtr.dll could not be restored to its original, valid version. The file version of the bad file is 1.50.1085.0 The specific error code is 0x800b0003 [The form specified for the subject is not one supported or known by the specified trust provider.
].

I have searched for a solution but to no avail. Does anyone have a link to a hotfix for this or any advice on how to resolve it? Thanks for your help.