Nope Firon, I have tried with serveral firewalls (Outpost, Comodo, Windows Firewall, Zonealarm, etc) and I have this CPU usage when the connection is between uTP. Nothing happend when the connection is TCP. I have a p4 at 1.7GHz and the CPU is almost 100% all the time when is connected to a uTP swarm, doesnt matters which firewall is.