How many days ago exactly did your LW stop running?

Your LW preferences will be found in a new location after running LW 4.10 & having deleted them once. Try step 3 here : Point 3 in Fixes for Limewire (sample image included.)

You might also want to update your Java. Uninstall your Java using the Add/Remove Programs Control panel. Then install Java 1.5 using the "Offline" installer version. See point #1 in above link.

These firewall issues are normall either due to software firewall or modem/router firewall. So ... unless something else is playing up affecting communication between LW & devices & firewall, then the issue must be one of these 2 things. Something might have become corrupted along the way. It's hard to know.