hmmm i did some more testing. I think I have an idea whats wrong. There are a certain number of posts that appear to show up at a certain relavacny to every search. So if your search returns no results then you get nothing but those posts.
Do a search on the word texture. I figured that would be a common word. You will get lots of relavent searches, but as you scroll down, and the relavancy decreaces you will notice those same posts popping in there as well.
Strange problem but I guess its workable since if your search does have results you will get them, and if you just see the generic posts, then you can assume your search returned no results.