Do you really need SP2? It's really only designed for major networks or if you have a business. Not for the average home user. A couple of options:
1. Uninstall SP2
2. Run a SP2 patch & follow the instructions HERE (click on link) & read up more HERE
SP2 reduces your connectivity & also changes your firewall settings back to default. Check your Firewall settings here: http://www.limewire.com/english/content/firewalls.shtml

You might also want to double-check you have up to date Java: Java 1.4.2 (click on link)