Searching in Outlook 2007 fails

If you have Windows Vista and you are using Outlook 2007, you probably like the instant search feature. Well, it stopped working for me. I tried to remove it, add it again etc in the “Indexing options” dialog. What fixed it is the step-by-step procedure in this article. But do note, that I added the outlook back to the search sources manually (because if I let Outlook add itself, no go).