For my DSL at home I use an Actiontec GT701W DSL modem, which is the one Qwest sends you. In fact, I'm merely renting it from them because I didn't know if I would want to keep it. The fact that the box continually has issues convinced me pretty quickly that I don't. I noticed something interesting though. It hasn't caused any problems for the last few months.
So I thought about why that might be and it occurred to me that about the time it started working well was when I turned off the wireless. See, I upgraded my home network to IPv6 and since the Actiontec doesn't support it, I put in a Linksys WRT54G which I have modded with OpenWRT. I decided to move the wireless over to the Linksys as well. That seems to be the point at which the Actiontec quit being a retard.
The lesson here is that Actiontec doesn't know how to make a complete system, even if it is based on Linux. But by carefully disabling the more broken parts (including the DNS resolver, which I long ago replaced with a simple Bind cache), you can get a more or less functioning network. Kinda pathetic, eh?