Cisco VPN :: 1941 Disappearing IPsec Routes With RRI

I am trying to set up a pair of 1941 routers in a HA configuration to act as L2L VPN gateways. The active router of the pair should distribute routes to the remote destinations using OSPF to internal routers. The VPN part is working fine and the routers are correctly advertising routes to internal hosts, however my problem is that when an IPsec sessions disconnect, the routes disappear and therefore internal hosts cannot reestablish a connection. If the remote end establishes a connection, the routes appear again and connectivity is restored.
 
My setup is as follows: (ASA) --> (pvpn01 & pvpn02 HA pair) --> (internet) --> (remote peer)
 
The other router in the pair has exactly the same config except with different interface IPs. The remote end is configured to talk to the HA address
91.216.255.248.The VPN routers are both running IOS version 15.0(1r)M9.
 
When I initially boot the routers, the route for 192.168.66.0/24 appears in 'show crypto route', and is advertised to neighboring routers. If I ping an address on that network an SA is established and stays active as long as there is traffic flowing. pvpn02#show crypto  route
 
If I then stop traffic flowing over the tunnel and wait until the IPsec SA lifetime is expired, the route is deleted from the system routing table and therefore not distributed by OSPF. The result is that internal hosts cannot reestablish the tunnel as the other routers have no route to the 192.168.66.0/24 network.
 
Is this a bug, or is there another way to get the RRI routes to persist on the active router?