First thing to try is 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.
LimeWire Pref Folder in Vista

Try uninstalling both ZA & LW (start > all programs > LW & use the uninstall option there), then reinstall LW. Once that's installed, reinstall ZA. That's been a fix for a few Vista users.
http://www.gnutellaforums.com/281366-post6.html

Were you using Java 1.6.0_02 when LW was working? Some people have had connection issues when using that update. Try this verion instead, if Java's not the problem then it's easy enough to remove this version & reinstall 6 update 2 Download the JRE offline installer & remove your current Java before you install this version.
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11

Did you use port forwarding instructions from the site below? If your firewall icon remains, go through the port forwarding steps again & check everything. Find your router in the list here, then choose LW from the program list.
PortForward.com - Free Help Setting up Your Router or Firewall
Make sure you've set up the static IP address properly & that LW's listening port, port in the 'manual port forward' box & port forwarded within the router are the same number!