There are several bugs in the search functionality in these forums. First of all, if you enter a search term in a forums main view's search edit box and hit enter, nothing is filtered out. I can search for "delegate" in the VC++ General forum and still see all the posts, and I'm sure that "delegate" is not a keyword in all the posts.

The 2nd bug is that if I use the search button on the toolbar for the forum site (between the home and my forums links), and then click "more search options" and click the "selected forums" radio button, it starts searching immediately and never finds anything. It doesn't give you a chance to actually select specific forums.