My Rev. I has been functioning well as a bridge for almost 50 hours. That's absolutely the longest period of time I've gone without a reboot in the past six months.
So, here's what I recommend for those who continue to have problems despite the range of tweaks -- IGMP off, UPnP off, etc.--we've suggested here. Note: This is not a solution. It's a stopgap until such time (if ever) Verizon releases a more stable firmware build. I chose this path since I didn't want to provision over ethernet or spend my own money on a third-party router.
1) Use an older router (ideally the Rev. F) as your primary. If you have don't have one readily accessible, request one from Verizon. If you want to continue to use the Rev. I's superior wireless speeds, tell them you want to keep it. And above all, don't agree to pay a single dime more than what you're already paying. Verizon should do all of this for free to ensure your network is reliable.
2) After you've hooked up the older router as your primary, disable DHCP and broadband via coax on the Rev. I. Then, assign a static IP to it and hook the router up to an unused coax port somewhere in your house. Turn wireless on if you want to use wireless N and enjoy! If you decide to use wireless on your primary router as well, make you sure you assign a static channel to each so there are no conflicts. (The Rev. F, by the way, has draft wireless N and while it won't give you speeds as fast as "true" wireless N, it might give you better performance than wireless G. So, feel free to tinker and use whatever wireless config works best in your home.)
Like I mentioned above, my Rev. I seems to working fine after I relegated it to a bridge. Plus, I moved it to a more central location, so wireless is even more effective now than ever before. I'm still not happy I can't use the Rev. I as my primary, but I really didn't have a choice.
Of course, you can also try the many, many router tweaks listed in this thread, but they don't always seem to work...at least not for everyone.
For more information on setting up the Rev. I as a bridge, go here and, assuming your configuration is the same as mine, start with step #2: https://secure.dslreports.com/faq/15984
You could also, as an alternative, simply hook the Rev. I up to your primary using ethernet. I chose to use it as a bridge in an entirely different room so I could hardwire a range of components (A/V receiver, Xbox, blu-ray player, etc.) to it.
As a sidenote, it's interesting that the chronically unstable Rev. I finally seems to work after scaling it back to a bridge, but I have no idea what that actually means. All I know is, it's finally stopped rebooting itself after almost half a year.
