We did plug in the SB5100 to see what would happen (famous last words, I know, but we survived it
).
Ended up with all 4 lights solid (power, receive, send, online) which I think means it was synced. Plugged in the ATA and still had the blinking red light.
I logged in to our Comcast account now and it shows the SB5100 belonging to us, along with the "Arris Interactive, L.L.C. TG862G" modem/router. I guess we own the SB5100 now.
Back where we started, the modem/router is cranking out 50/10 (theoretically) and the ATA status light is blinking red. I guess next step is to contact Comcast but I'm reluctant to do that (I figure the advice here is already 3rd-tier, so why go back to deleting my cache and clearing my cookies and restarting Windows?).
I may not be able to do that tonight, so any additional advice will be appreciated.
Thanks again!
=aw