I have almost the exact same setup as you do--except I have a G3--with the exact same problems. Paradog's suggestion might work so try that. Here's the suggestion I used. It worked for me! (I'd make a link to the thread for you but I don't know how to do that )

!! - router4.limewire.com down - !!

router4.limewire.com appears to be down atm. Since this will surely cause some connections problems, here is a list of alternate quick connect hosts, you can try.

connect1.bearshare.net
connect2.bearshare.net
connect3.bearshare.net

connect1.gnutellanet.com
connect2.gnutellanet.com
connect3.gnutellanet.com
connect4.gnutellanet.com

gnutella.hostscache.com

gnet2.ath.cx:6346

HOPE THIS HELPS!!!