I've tried over 10 different version from 4.13-4.14, and have tried it on Both JAVA 5 Update 11 and Java 6 Update 2, neither works. Limewire won't connect and says I'm behind a firewall. The only thing I have running is NOD32, I have DMZ enabled, and my router firewall is disabled. Windows Firewall isnt up either.
1. OS version? Windows XP Service Pack 2
2. What firewalls you have? Noone
3. How much ram? 1.5Gigs
4. Hard Disk space available? 480 GBs
5. Connection type? Cable (Time Warner Cable)
6. Modem & router brand name & model numbers? Linksys WRT54GS
7. Where are you trying to connect from (home, school, work, etc.)? Home
8. What version of LimeWire (LW) & Java do you have? I've tried 4.13.12, 4.14, 4.14 beta, 4.13.13 and java 5 update 11 and java 6 update 2
9. Who is your ISP provider (Internet Service Provider)? Time warner cable
10. Do this simple test for us. Using your browser go here: http://www3.limewire.com:6346/ The page should say 'Your test worked!'. What happens when you go there? Worked
11. Are you sharing the connection with other computers or p2p sharing programs? Sharing internet with 2 other computers through the router.
12. Is this a your 1st try at LW or is this a new problem with an experienced user. Been using it for 4 years
13. Do you see a brick wall in front of the blue world icon at the bottom of LW's interface? Yea theres a brick yet I have NO FIREWALL

First thing to try: Delete LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location).
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.

Just for now, stick with the Java 1.5.0_11. Remove any other Java versions that you have installed.

Try port forwarding for your router, the instructions are here.
Port Forwarding for the Linksys WRT54GS
Don't forget the step of setting up a static IP address first (or port forwarding won't work). LW's lilstening port, port in the 'manual port forward' box & port forwarded within the router all have to be the same number

I have full connection but a firewall is present. I have turned off the only firewall that I know I have.
1. OS version? Windows XP home edition ver. 2002 service pack 2
2. What firewalls you have? microsoft
3. How much ram? dunno
4. Hard Disk space available? dunno
5. Connection type? Cable - Comcast
6. Modem & router brand name & model numbers? netgear wireless cable modem gateway CG814WG v2
7. Where are you trying to connect from (home, school, work, etc.)? Home
8. What version of LimeWire (LW) & Java do you have? 4.12.11 and java 6 update 1
9. Who is your ISP provider (Internet Service Provider)? Comcast
10. Do this simple test for us. Using your browser go here: http://www3.limewire.com:6346/ The page should say 'Your test worked!'. What happens when you go there? Worked
11. Are you sharing the connection with other computers or p2p sharing programs? no, only computer that we have.
12. Is this a your 1st try at LW or is this a new problem with an experienced user. Been using it for 2 years just got the firewall problem after my wireless modem crashed and they installed another one
13. Do you see a brick wall in front of the blue world icon at the bottom of LW's interface? Yea theres a brick wall, however, I have full connection. the microsoft firewall is turned off

Why would I need to port forward if I got DMZ enabled? It opens all the ports anyway doesnt it? And I deleted my limewire folder and it still gives me the same problem.