You have the dreaded Intel Puma chipset in that modem. Do a search on Google and you'll see what I mean.
Did Comcast supply the modem or did you buy it yourself? Either way, get a new model of modem.
I know I'm bumping this thread, but I have to give another shoutout to Moen.
We've been in our house for 20 years now and the original Moen shower faucet handles are still installed. I called Moen about 10 years ago because both were leaking and they sent free replacement cartridges as part of...