I am using the cisco VPN client 4.6 to connect to my Cisco 837 however I cannot see the network connected to the ADSL router. I can ping and telnet to the internal interface and can ping my connected machine from the network on my ADSL router.
If you can ping the inside interface of the router then your config is OK, certainly I can't see anything glaringly wrong with it.
Check that the default gateway on all your internal machines points back to 10.10.10.1, or at the very least they have a route to the 10.12.12.0 network pointing to 10.10.10.1.
If that's OK then it may be a switching bug in the router code. Try enabling "ip cef" on the router. If that doesn't work try turning off fast switching with "no iproute-cache" under the dialer interface. there was a lot of old bugs with fast switching but they should all be ironed out long ago, but they do seem to crop up every now and then and they do have these symptoms.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...