This seems to work only off and on.
I was looking for book reviews so I tried
books biography as search terms and got many hits.
I figured there must be many song and album specific threads here somewhere so I tried some song titles and album titles and got error boxes every time.
sure - at first I thought it was more than 2 terms not connected by "+" and not enclosed in quotes
but then I got it with various song titles in quotes
for me this morning:
"LOVE OF MY LIFE" -- gets results
"ANOTHER ONE BITES THE DUST" -- gets the error page
(not that I'm actively looking for either - but they do raise the error condition)
by the way - thanks for the hint about the general site search - not quite as convenient as searching only for posts within the forum, but it does do the job.