I dunno, it worked for me. I chose:Keyword(s): a
Search Which Forum(s)? Search all forums
Search which field(s)? All
Search how many days in the past? Last 1 year
Search the Archive? Yes
And it picked up all the board that have messages (I think) and an archive (it even picked up the old spotlight boards that are deactivated, but still exist). Right now, the only messages in any of the archives are those I have put there.
The board system currently only archives messages when there are over 300 threads (not individual messages) and none of the boards have reached that point yet.
Tools for your Wizardry(r) toolkit