The answer is kinda convuluted --

The number in the search tab (in the parenthesis) is calculated one way, and the number in the # column is calculated another way.

The # is the number column is the number of unique hosts that have that file. One result can tell us of multiple hosts, and conversely multiple results (for a single file) can be from the same host (if the shared file is listed multiple times in your library).

The () numbers are the number of results we've received, NOT including all the additional hosts that each result told us about.

Yeah, it's confusing and unnecessary and kinda wierd... We're looking at making the numbers synch up better for the next version.