I have 2800, connected to the Internet using DSL.
i am trying to create VPN Tunnel (site-to-site) but failed.
I don't know if the problem is on the ADSL.
Interestingly, I can see the tunnel up and passing traffic in the new show outputs, I am not sure why this is not working for you.
Try this on Router (10.40.x.x)
ping 172.18.1.254 source 10.40.0.1
Does this ping work ?
What ip address you are trying to ping across the tunnel and from what ip address ?