I have a new ASA 5520 running 7.2 that has a tunnel to a Concentrator 3030. The tunnel comes up fine, but I only see data being transmitted from the ASA and not received. The concentrator show both recieved and transmitted data. The data is originating from the ASA.
The topology is very simple for the ASA Internet -> ASA -> Private network.
The tunnel comes up right away and sends traffic, but doesn't even see it on the come back on the outside interface.