Did you notice if your cable modem ever goes online(online light on the modem goes green)?
If your modem never even gets online then it could be that you didn't wait long enough when you power cycled your equipment. In my experience with comcast cable modem, they somehow store the MAC address of the router that is hooked up to the modem the very first time you turn on the modem and router. This MAC address is kept even if the modem/router is turned off. I think it resets in a few minutes so you might want to try that first. If that doesn't work, the next thing I would try is to set up the Ooma hub to use MAC address spoofing and copy the MAC address of the old router to the Ooma hub.
I hope that helps.