I'm not sure why you'd need SP2 if you'e not running a company network. That's what it was designed for. But people tend to update without investigating what it's for & whether there's been any problems with it. There is a patch for it but it doesn't work for everybody. In the connections section there's a sticky or 2 about sp2.
You could try this: Repair LimeWire using the Add/Remove Programs utility. Go to Control Panel then Add/Remove Programs & click on Limewire on the Change/Remove button & it comes up with options and one of them is Repair.
You could instead try the beta 4.3.2
http://www.limewire.com/english/content/beta.shtml or an earlier version
http://www9.limewire.com:82/download/