I'm getting this exact same issue on one of my primary servers. It's odd because I have 3 primary servers all built the same and yet it only happens on this one.
I found this KB article with a hotfix available - but at the moment, the website isn't avaailable for some reason. If I manage to get on it and get the hotfix I'll let you know how it goes.
http://support.microsoft.com/kb/982399