I am having exactly the same problem and have tried almost everything too! I have:

Asus MB with Intel Pentium 4 - 3GHz
1GB DDR RAM
Integrated Intel LAN
Netgear ADSL Modem
Belkin 54g Wireless Router
Connected by BT Broadband - ADSL @ 512kbps

I have StopZilla! installed and I am currently running Windows Service Pack 2 Beta/RC2(a legal copy as I am a registered tester!)
I am also running Norton SystemWorks 2003 and Norton Antivirus 2005 Beta (again legal copy!)
Finally AdAware Professional is also running

Windows XP Service Pack 2 - this installs the new Internet Firewall which I am also currently using. I have added the LimeWire port to this and all is ok with that.

I have tried everything from reinstalling it, to downloading the latest version, to restarting, disabling firewalls, enabling ports disabling all above mentioned software and even hard-booting my modem and router.

Nothing seems to work. LimeWire SOMETIMES connects and displays "Poor" or "Good" but then goes back to "Connecting". I have noticed that sometimes after a reboot if you go straight into LW and dont load ANYTHING else it works for a while. Also as soon as you load a new Internet browser window it cuts the connection.

I dont think its anything to do with the Firewalls as the connection isnt working with or without them on.

Really stuck...can anyone help?!!

Thanks,
JameZ