If you've reset the router to default, there should be no need to access the configuration page 192.168.0.1 (or whatever it is these days), the router should just detect the modem and type of connection automatically.
It is important you do restart them in that order and allow the modem to get a steady state (around two minutes) first, before starting the router up, for the reason in my original post.
The router can only detect the modems connection if the modem has been rebooted.
I've been using cable modems for 10 years and over that time at least five different routers and never had a problem... So it should just work.. Honestly!
Patrick
---------- Post added at 10:18 ---------- Previous post was at 10:13 ----------
This might help
See page 7-4 of the manual
here
Patrick