L2TP VPN Requires Manual Reset after WAN Reconnect

[RoadKill]

I recently bought a 7402NX to use with my Huawei E367 3G Modem, as default WAN connection (not fail-over).
Apart from some bandwidth reduction compared to direct USB connection, it generally works OK.

Sometimes the ISP connection drops, usually the 7402NX reconnects the modem automatically. When this happens, if a dial out VPN tunnel is active, I have to deactivate & reactivate it through the 7402NX web interface to re-establish a tunnel.

As the modem IP is dynamically allocated, the tunnel is almost certainly invalid after a reconnect. This may also happen with an ADSL WAN connection, but I can't test that.

Can the 7402NX be made to re-establish a tunnel automatically instead of clicking through the web interface?