Errors over VPN - message authentication code incorrect

Hello,

I am getting errors when transferring data over my VPN.  I'm not sure why. I've recently replace the gateway / firewall device. Previously, this VPN was stable and these types of transfers worked without error.

Here is an example.  mydev is behind the firewall. r720-02 is accessed over the VPN

[12:04 mydev dvl ~/tmp] % time scp -r dvl@r720-02.vpn.unixathome.org:bacula.dump .
bacula.dump              0%    0     0.0KB/s   --:-- ETAFssh_ssh_dispatch_run_fatal: Connection to 10.10.0.217 port 22: message authentication code incorrect
scp: Connection closed
scp -r dvl@r720-02:bacula.dump .  0.14s user 0.01s system 21% cpu 0.665 total

If I try the scp direct, without using the VPN, the copy succeeds.

Ideas please?
-- 
  Dan Langille
  dan@langille.org