The following issue is caused by a known bug in SCOM 2007 and Microsoft is working on a resolution:
This issue is documented and acknowledged on the official Microsoft feedback site:
https://connect.microsoft.com/OpsMgrFeedback/feedback/ViewFeedback.aspx?FeedbackID=330210
In the Alert Details, Click WMI Probe Module Execution Failure.
Select the Overrides tab. Click Override. Select For a Group…
Select Windows Server 2000 Computer Group.
Change Enabled from True to False. Store the override in the Windows Server 2000/2003 Overrides MP. Click OK.