Based on what you posted so far, I would guess one of the following possibilities:
* Your new DSL service could require different router settings than the old DSL service. (More changes than just a username password change.)
* Related to that - Did you get a new modem with the new service or are you using the same modem? If you are using a new one, is it one of those that has a built in router?
* defective router or a bad ethernet cable.
