Occasionally in your Operations Manager event log you might see these 2 events: 21041 and 21027.
Event ID: 21041
Operations Manager has received a bad configuration file for management group TheSCOMLab which could not be parsed. Configuration has been re-requested. A copy of the bad configuration file will be placed in C:\Program Files\System Center Operations Manager 2007\Health Service State\Connector Configuration Cache\TheSCOMLab\OpsMgrConnector.Config.Error.xml
And this one…
Event ID: 21027
OpsMgr has received configuration for management group TheSCOMLab from the Configuration Service, but failed to process the configuration. Configuration will be re-requested. The current state cookie is “” (State cookie may be empty if there is no active configuration)
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
There is a problem with this server not being able to parse the XML files provided by OpsMgr. This server will require msxml6.msi to be reinstalled. You can find the msxml6.msi file on the SCOM Installation DVD. Install the file and restart the Health Service.