Sounds like you may not even be properly connected to the Gnutella network.
1. It does look like a firewall issue. You may need to remove your previous XP firewall rule for LW & re-add it.
User Cant Connect - LimeWire or manual instructions here
Windows Firewall - LimeWire
2.
(a) go to LW's menu bar, Tools > Options > Connection & disable option. Then when you wish to connect, go to File menu > Connect. You may have too many incomplete files which are affecting LW's communication with your wireless router & causing a firewalling effect.
(b) Tip: Purge the Downloads Queue! (click on blue link) will help freshen up LW & hopefully reduce chances of a breakdown in communication between LW & your dsl router getting UPnP to work as soon as it connects.