Make sure the windows firewall hasn't been enabled. You are being blocked either by a firewall or Alltel has started blocking P2P apps if you don't have any firewalls running the it is most likely Alltel give them a call and ask them if they have started blocking P2P apps. You might find the link below interesting it is about ISP that block or shape p2p programs.
http://www.gnutellaforums.com/showth...threadid=33712