A registry file that performs the repair suggested by this KB can be found here.
I've noticed this error cropping up after applying SharePoint updates to a new installation of Small Business Server SP2. I think the change was made in the updates, because the error doesn't crop up prior to updating SharePoint Services 2.0.
Also, make sure that the "Sharepoint Timer Service" is set to run under the "LocalSystem" account. These two things should stop the error from occurring every 5 seconds.