A glitch? Different times the search was performed?
I have tried this:
http://www.diynot.com/diy/search/5276598/?q=rothenburger&o=date
http://www.diynot.com/diy/search/5276599/?q=rothenburger&o=relevance
Both have 134 results. It's a strange one, I will keep an eye on it.