Limewire Basic worked fine, just got greedy and wanted to try for more speed with Pro. Kids managed to do one search with Pro, not sure how but disabled firewall I think. Now it won't work even with firewall disabled.
win XP
Limewire 4.12.11 pro
Java 1.5.0_03
Dialup
modem conexant D850
Mcafee Personal Firewall Plus 7.1.113
Provider Bigpond
My Test worked!
Not sharing
Router ????
Ram & disk space ??

Try reinstalling Java. Use the JRE offline installer & remove your current Java before you install the newer version.
Java SE Downloads - Previous Release - JDK 5

Next, delete LW's preferences folder when LW's properly closed. See point 3 below (also point 2 if you've used much older versions of LW in the past...there could be a folder in both locations).
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through & reset things afterwards

That might be all it takes...it's always a good idea to delete that prefs folder after updating or upgrading LW. If you still have probs, double check that your XP firewall is off & see if this link helps for configuring McAfee.
Port Forwarding for the McAfee Security Center

Also this one. Choose your firewall from the dropdown menu on the left & then choose configuration/features.
McAfeeHelp Technical Support

Ok!! After an entire day of fiddling around with it, I have got the firewall off the earth symbol. Now I can do good searches and dowload songs but videos just keep saying "awaiting sources". I have a turbo connection.

You're probably encountering fake files.

http://www.gnutellaforums.com/showthread.php?t=63993
http://www.gnutellaforums.com/showthread.php?t=56904 (applies to video also)

Good Luck

Dano