Rjmmoon,
Your idea of power cycling is a good one. I've restarted everything muliple times, including taking the batteres out of the thermostat and rebooting all networking equipment and my computer. The 3 hour time difference remains. It would be nice to know if the security hub is the problem, but I don't know if Comcast would replace it after a year of sitting in the closet.
I didn't install the system until recently because it was basically the result of a sales pitch that would lower my bill for a while.
Thanks.