I got this error event on my MOM server for every MOM agent I have in my environment.

Event Type: Error
Event Source: DCOM
Event Category: None
Event ID: 10006
Date: 22/08/2002
Time: 02:06:06 ص
User: MYDOMAIN\MOM
Computer: MOMSERVER
Description:
DCOM got error "Class not registered" from the computer MOM-AGENT when attempting to activate the server:
{7623E890-5680-11D3-A463-00A0C9AFE040}

Contributed By: Mike Betts [MVP MOM]
You can safely ignore this error.