Source: Kevin Holman's OpsMgr Blog

"One step it seems people often overlooks when upgrading to OpsMgr 2007 RC1 SP1 - is to update their management packs.

The management packs that ship with the product are RTM version (6.0.5000.0)

Often, users will have updated many of their Management Packs to the latest version available on the web.... from the catalog:

http://www.microsoft.com/technet/prodtechnol/scp/catalog.aspx

However.... a step often overlooked when upgrading to the RC1-SP1 version of OpsMgr - is that you should update your MPs to the SP1 version.  These are included in the SP1 media in the \ManagementPacks directory.  The correct version is 6.0.6246.0 for RC1-SP1 MP's."

Read more at source.