Hope you don't mind if i add my settings to this thread, but i'm having similar problems...i only get the "connecting" symbol and after a while it tells me i have no good connection / firewall blocking connection:

CPU - Athlon64 3000+
OS - Windows XP Pro (SP2)
HDD - Western Digital 120Gb
RAM - 512Mb Crucial PC3200
LW - LimWire 4.81 (non-Pro)
JVM - Java 1.50.02
Firewall - Hardware router firewall (ports 6300-6400 open manually)
Router - Netgear DG834G (wireless)
Connection - ADSL 512/128
ISP - PlusNet
Home Connection

I know all the ports i have opened are fully open, apart from 6346-6348 which appear to be permanantly blocked. I'm currently trying to run LimeWire on port 6340 which i know to be open. I also tried a working socks v5 proxy with no luck. The bug report shows "false" for incoming connections, but i have disabled the windows firewall and have no other firewall / anti-virus programs installed.