If you visit the last page of a result set with multiple pages then use the text box at the top to constrain that search further, the URL puts you on the last page of the previous result set so you see "No Search results found. " but "Page 10 of 2 results" indicating results were found. You can see this by choosing "CCSM" from the project facet, then visiting the last page of the results: http://search-esg.prototype.ucar.edu/search?page=10&Project=CCSM

Type "b20.007" in the text box and hit "Search".