i am running a cisco VPN client connection to an external network through a Cisco ASA 5510. Basically my laptop sits behind the the ASA, then the VPN Client from here connects to a Cisco VPN Concentrator 3000. The tunnel establishes but I am unable to receive traffic back? I can see packets are sent and encrypted but not received and decrypted?

Checked on out syslog server and I get the following error:

Regular Translation creation failed for protocol 50 src (my Laptop) dst (external VPN Concentrator)

I thought it would be some kind of NAT-T problem but this is turned on on the ASA, and I am assured this is turned on on the VPN Concentrator the other end, could something else need to be configured on my ASA?