Update 6/22/09: KB972041 is out with a hotfix that resolves this issue
[http://support.microsoft.com/?kbid=972041]. I guess you install it before, or
in lieu of KB967831.
OK so this blog post
[http://blog.tiensivu.com/aaron/archives/1867-RtcQmsAgent-fails-to-start-on-OCS-2007-R2-server-and-causes-KB-967831-April-2009-update-for-Front-End-Server-components-install-to-fail.html]
explains it well but it has