Doing an advanced search for "Search problems" using "search entire posts" and "Show Results as Posts" does show the posts with the title of "Search problems" which has to include all posts in the thread without a different title used in that post. Besides, the original post in every thread has to have the same title as the thread, so even if every other post in the thread had its own title, the original post would still have to show up in the search I described above.
This will still not find all posts with the key word..
Here is an example. Do a standard search for the key word “bumble bee” in the “Free Travel Contests and Sweepstakes” forum. Do it again as you suggest doing an advanced search for “search problems” using “search entire posts” and “Show Results as Posts”. These searches will only return one result. Do the search again but change it to “Search Titles Only” You will find that it will find my post on 3/8/08. The standard search is not returning posts that the key word is only in the title and not repeated in the thread. Do these searches again with the key word “zippo” in the same forum. When I do a search I want it to return ALL references to the key word.