For people who care: I figured it out.It seems that since I upgraded to testing lo (loopback interface) isn't broadup at boottime. I don't understand why by the way. I have a line saying 'auto lo' in my /etc/network/interfaces.
Further more I had to make a line 'ALL : 127.0.0.1' in my etc/hosts.allow to make it work. Otherwise the TCP-wraper woudn't allow the connection.
Tim