since comcast updated my firmware and finally fixed all the reset/reboot problems, I got access to the sb6141 web pages at 192.168.100.1 and see now that i have the normal 8 down bonded channels, but just one upstream channel (no bonding at all).
Been through chat and live support re: the reboot issues and it was like getting teeth pulled. Is there a tech support for 'no' bonded upstream channels issue?