Myself and Ktwhy have experienced the exact same router/cable problem with telstra (starting on the same day, using different hardware), in that the router will not work connected directly to a modem (see topic: HELP with TCL Cable modem connected to a router.... ) - router hardware, firmware and settings are all fine.
It turns out our IP Addresses are both in the range 218.101.50.*. We have tried everything and have become convinced the problem is with telstra and their network.
Of course telstra deny this (maybe rightly so, or maybe not).
So.... are there any other users out there in this IP range, who successsfully use a router directly? Or other users with the same issue?