Too often I can't find previous articles despite providing excellent search queries. For example, if I know most of the words in the TITLE and the original poster's USERNAME, I still might get zero (0) hits. Perhaps the search form should just redirect input to google appending site:forum.bitcoin.org ?
Remember that the search is always done in the context of the page you were on. Always do you search from the home forum page if you don't remember where it was posted.