The SharePoint team has released post-SP1 hot-fix rollups for both WSS and MOSS. If you haven't installed SP1 yet, be sure to take some time to plan your deployment. And then review and install these rollups:
WSS Post-SP1 Rollup: http://support.microsoft.com/kb/941422
MOSS Post-SP1 Rollup: http://support.microsoft.com/kb/941274