I have been having an odd problem for a while. We have an ASA 5520 in our datacentre with a 5505 in our office and a 5505 at one of our clients connecting to it. We use the VPN to our client to replicate their VM's. The problem is when the VPN from our office to the DC rekeys it causes the tunnel to our client to drop packets and the replication fails, sometimes the tunnel locks and needs to be reset before it will work again. By locks I mean it shows up as a live tunnel but there is no traffic through it.
All of the ASA's are running Asa821-k8.bin.
We have been scratching our head for some time and any help would be gratefully received.