This has worked for quite a few Vista users: Uninstall both ZA & LW (uninstall LW via start > all programs > limewire & use the uninstll option).
Next, reinstall LW & make sure to use the offline installer (cancel the dialog box which pops up when you click to download LW & choose the option to download the offline installer).
Finally, reinstall ZA.

In LW file > disconnect. Wait 5 mins, then file > connect.
In LW tools > options > connections, make sure that 'connect on startup' is ticked.

Try port forwarding for your Linksys. The instructions are here.
Port Forwarding for the Linksys WRT54G
Don't forget the step of setting up a static IP address, or port forwarding won't work!
LW's listening port, port in the 'manual port forward' box & port forwarded within the router should all be the same number.

If you still can't connect, try using this older version of Java. Download the JRE offline installer & remove any other Java versions on the computer, before you install this one.
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11

didn't mean to post behind you Remoc!