1. Double check your mcafee firewall to make sure LW is on the safe list.
2. Try deleting your LW Preferences folder whilst LW is
closed; instructions here:
Point #2 & 3 in Fixes for Limewire (sample image included at bottom of page.)
3. Pipex is a reknown problem ISP, see more about them here:
ISP's known to BLOCK or Filter p2p or specifically Limewire