Stupid modem

Whenever I open up my web browser (Firefox... or IE), I get this message (check pic). I then clear my cache on both browsers and it lets me surf until the next time I open the browser and it gives me the same message, and I do the same thing.

What should I do? I have a Westell DSL modem if that helps.

yeah, I gotta use BellSouth crap DSL. I think my problem fixed itself though, its not giving me this message anymore