I just had a failover between my pair of 5520's and during the failover I dropped all my ipsec vpn connections. I have statefull failover configured which is supposed to keep all that up and running during a failover. Below is my failover configuration....
failover lan unit primary
failover lan interface failover GigabitEthernet0/3
failover polltime unit 1 holdtime 3
failover link failover GigabitEthernet0/3
failover interface ip failover 172.17.1.1 255.255.255.0 standby 172.17.1.7