We can start by looking at Java as the 6.1 has caused some connection problems with many users latley...
Do you still have the old Java that was running fine with your 4.8 if you do uninstall Java 6.1 you can do this by going to Add/Remove programs...
Another member had the same problems and didn't have the previous Java he had been running with the 4.8, so he had to update to the latest version of limewire and run Java JRE 5.11...
Another issue is your router it has a Nat Firewall and if you had a later version of limewire the wall would be there in front of the globe...
Your best bet is to Port Forward to let limewire pass through...
These are your instructions..
Port Forwarding for the Netgear WGT624