If you haven't been using it in awhile or you just installed it, then your host cache may have gone stale. Try refreshing it with this file: connect.zip
Just unzip it into C:\Program Files\BearShare\db with BearShare shut down, and then restart it.

Oh yeah, before I forget, try the version in this thread too, because you can shift it into ultrapeer mode,
which is much stronger at finding peers to connect with.