I have inherited 2 VPN 3005's one is in production with a weird config, probably because whoever set it up was having a similar issue. The other I am trying to setup properly and will then move the users to it. It has a public IP and the private port has an address on the local network. I have setup a pool with a different subnet. My client connects but, cannot get on the local network. I can ping the local interface of the 3005 but, nothing past that.
If I understand correctly, the tunnel is establishing properly (so no problem on the VPN config).
If you check under Monitoring | Sessions do you see the remote access session established? Also do you see packets received/transmitted?
I would check that the internal LAN has a default gateway pointing to the internal IP of the concentrator (or at least a route to get to it) to be able to send packets back to the VPN clients.