[cheebacheeba]

Yeah what they said about manually entering in your IP and all those other number.number.number type things in the internet settings occasionally works.
Had the same deal happen to a lot of people on the Playstation network too, where even a wired configuration would inexplicably "forget" its associations and just not work.
The power cycle thing sometimes kicks it in the ass too.
Though if you've changed your actual internet type...is that a setting you can indicate too?

All I can really suggest for now is completely power cycle the modem, then go through your internet settings from scratch, entering in as much information manually as you're able...your ISP should be able to provide you with the relevant details.