In LW go tools > options > advanced > firewall config, and if it's set to UPnP change it to Manual Port Forward. Now Change the ports to 64049(listen on port and manual port forward), or something in the range of 49152 - 65535. Click Apply to save the change. Then make sure the new port numbers are allowed through your firewall.
Try deleting LW's preference folder with LW completely shut down. See point 3 in this thread:
Fixes for Limewire. This will reset all your option settings, so make a note of them first.
Try this, with LW shut down go to the add/remove programs control panel and uninstall your current version of java. Now download and install
J2SE Runtime Environment (JRE) 5.0 Update 11(use the offline installer):
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11