Disable the XP firewall & configure the Norton firewall to allow LW.
http://www.gnutellaforums.com/226610-post6.html
PortForward.com - Free Help Setting up Your Router or Firewall

Try changing ports. In LW go tools > options > advanced > firewall config. Change LW's listening port to 64049 (or something in the range of 49152 - 65535) > Apply > ok.

Has the connection problem started since you updated your Java? Some people have had problems with 1.6.0_01. If the connection problem ties in with when you updated Java, try using an older version. Use the JRE offline installer & remove your current Java version before you install this one.
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11

Have you tried connecting at different times of day? One person here thinks Batelco are blocking p2p from 9am to 6pm.
Moey’s » Your ISP is cheating? How fast is your internet connection?

You could try deleting 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.

Try to find out the brand & model of your modem/router. If nothing's showing on top of the device, have a look underneath.