After spending years and lots of money trying to find a solidly reliable ADSL MODEM/Router I have given up. I have had loads of them, from Netgear, LinkSys and Belkin and they have all, ultimitely been a let down in the reliability department, needing reboots weekly, daily or when I tried to carry out a particular task.
In the end, I bought a sperate ADSL modem and a Buffalo Wireless Router (Runs DD-WRT and has USB Port) for less than £100 and they are rock solid together. I don't have to reboot the set-up either every few days, when doing a modest amount of downloading from iTunes or when playing a couple of hours of XBox live.
I wouldn't go back to an ADSL Modem/Router now.