Some people have had connection probs with that latest Java, try this version instead. Download the JRE offline installer & remove any other Java versions before you install this one.
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11

If that doesn't help, 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. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.

Looks like the port test page is acting up, try that again later on tonight or even tomorrow & see if the page can be displayed.

Did you see the firewall icon when you used LW on your XP machine? Try port forwarding, the instructions are here (for SBG900, pages are probably the same for your model).
Port Forwarding for the Motorola SBG 900
Don't forget to set up a static IP address. LW's listening port, port in the 'manual port forward' box & port forwarded within the router should all be the same number.