An advnaced search with the only limiting factor as Bitrate does not seem to work.

If I go to the Advanced Search page and select "Bitrate equals 192" as my only search constraints I get "empty" as my search result. I know this cannot be true as the majority of my music collection is 192kbs mp3s. I get the same result if I try "Bitrate less than ..." and "Bitrate greater than..."