CamelPilot
Thanks, I've been there already, my router works as a firewall and all ports are shut and locked.
As already mentionned, it was just a matter of curiosity, I was just wondering if it was some kind of worm attack or some peer-to-peer stuff, inherited from the previous owner of the IP address (My ISP changes addresses quite often).
As it's gone today, I'd go for the peer-to-peer hypothesis.