It worked just fine at my old apt idk what's wrong now and the people at comcast told me to check the ps site. That didn't help and neither did googling the error code. I posted a topic on the ps3 online board but its pretty dead.
Are you using wireless? Usually DNS errors dont matter. If you go to test connection, as long as you're internet connection is successful, you can get online. I can teach you a way to use the wired connection, which is really good.