I eventually got around to setting HA up with an additional 3910 in my setup.

It appears ive got things working as it should apart from one thing I dont understand.

I have it set to config sync every 7 days, or at least I think thats how it should work, but what appears to be happening is that any minor change, even ones to change some routing, the primary kicks off a sync and reboot of second box instantly, well after a 55 second wait actually according to syslog.

Is this normal or do I have it setup wrong somewhere.

Setup as hot standby, 3 WANS into 3xG1080 feeding both.

Everything apart from the constant reboots it behaves as I would expect, which incedently is where a DHCP fed WAN wins over the other two pppoe connections, as its there almost instantly on second box where as the pppoe can take 20-30 seconds to redial there connections.