I've heard of many people staying at dorms having problems connecting to the gnutella network. It's often a school policy to not allow p2p sharing so they either block or shape the bandwidth that can be used. An example of a gnutella shaper at a school is here: Bandwidth Shaper Sample - typical of how some schools & ISP's use it (click on link) ie: giving priority to net surfing & low priorities to p2p sharing.

Perhaps a proxy might help. Unfortunately I don't know about BearShare's abilities to handle proxies. But tips can be found particularly on page 2 here A Fix for those whose ISP's block Limewire pages 1 - 3 which have links to alternative instructions. (Sorry the link "is" is the LimeWire section but same principle applies! )