As I was toying with RCDC’s in my lab environment I was performing iisresets occasionally. Never had any issues. However when implementing my changes in the Acceptance environment one of the nodes of my FIM Portal servers failed to display the portal after an iisreset. Luckily Jorge blogged about this in June, and I remembered the article. The article of Jorge:
http://blogs.dirteam.com/blogs/jorge/archive/2010/06/29/windows-sharepoint-services-3-0-breaks-after-installing-update-ms-kbq983444.aspx

I went on and checked the installed hotfixes, and the one mentioned by Jorge (KB983444) wasn’t there:

However I saw that a new hotfix became active at the time (day) of my iisreset: KB2345304. It’s pretty clear this hotfix supersedes the previous one. It also mentions this exact issue in the KB article so the solution presented by Jorge still works. Just wanted to warn people out there, this hotfix sneaks in with WSUS/SCCM distributed updates and still seems to cause troubles like in June. My advise would be to install it during the build of your FIM Portal servers although I’m not sure whether a following hotfix won’t possibly break it again…

Thomas, who killed my WSS?!, Vuylsteke

P.S. Not 100% sure if it’s related, but the “SharePoint Services Search Refresh” time job was suddenly enabled again at the same time the hotfix came active… This caused an error and warning every 5 minutes in the event log… This can be disabled in the central administration: operations: timer job definitions section.