I'm having the same problem as well. Every time I activate the Advanced DMZ and set it to my airport extreme router, I'll loose my internet connection after a few seconds. But when I refresh one of the Actiontec config pages, the internet connection comes back (for a few seconds) and then disappears again. This repeats over and over again. The funny thing is, my father has the same setup and configured the same way and his works with no problems at all.
Very confused??
Very confused??