1. OS version? windows xp, admin account
2. What firewalls you have? only the basic xp..
3. How much ram? 40 gb, 30 free
4. Hard Disk space available? yes
5. Connection type?comcast (eg: dialup, broadband, cable, etc.)
6. Modem & router brand name & model numbers? LINKSYS wrk54g
7. Where are you trying to connect from (house, appartment complex, school, student accomodation, work, etc.)? house
8. What version of LimeWire (LW) & Java do you have? im using 4.1.8 but im willing to upgrade to 5, and ill let u knw if it says anythin about the firewall.
9. Who is your ISP (Internet Service Provider)? internet explorer.
10. Do this simple test for us. Using your browser go here: your test worked.
11. Are you sharing the connection with other computers or p2p sharing programs? umm wifi with iphone.
12. Is this a your 1st try at LW or is this a new problem with an experienced user. new problem
13. (a) Do you see a brick wall in front of the blue world icon at the bottom of LW's interface (only for LW 4 users)? yes _ (b) How many red or green bars do you see at bottom left of LW's screen? all green (all red or grey or only 1 or 2 green bars means disconnected)_ click here to see LW 5 Sample image, OR click here to see LW 4 Sample image
If you're using LW5, there's no firewall icon. In LW go tools > advanced tools...there you'll see whether you're behind a firewall or not.
Click on thumbnail to enlarge the image.

14. For those using a modem/router, how is your modem/router set up...are you port forwarding or is UPnP enabled? idk what that means.
15. What security programs are you using (antivirus etc)? Some people might not be aware that their security suite includes a firewall umm, just the xp one
16. What country are you living in? Sometimes there are ISPs with the same name in more than one country (eg Clearwire in the USA & also in Ireland). usa
17. Has anything in your setup changed recently? Have you updated your version of LW or Java? Have you added any new software or new hardware? Have you updated any software? Have you moved house, changed internet plan or ISP etc etc?
updated to lw 5.1.8

Unfortunately not all Linksys devices are good! The 54 range & especially the 54G range have firmware problems which Linksys never fully fixed. The effects are unreliable connection when run in both wireless & UPnP mode.

Probably first thing to try is deleting your LW preferences folder. Check various options here If LW 5 Will Not Connect

Best thing is usually to port forward the device for those models. The default port of 6346 is not necessary & can choose any port but best to choose are in this range 49152 - 65535. But make sure you do NOT choose same port as any other program uses. Router will reserve one port per program per computer. Set up Static ip address first is mandatory step otherwise the process will not work. PortForward.com - Port Forwarding Guides Listed by Manufacturer and Model & LW settings for LW 5 here: Manual port forward instructions & sample image