Brake light coming on, brakes spongy and surging

I have already been to the dealer to have the rotors changed and brakes replaced while in warranty. Now I am having a problem with the brakes surging and the brake light coming on. When I turn off the key and turn it back on everything resets itself, the light goes off and the brakes quit surging. I took it in once and they could find nothing wrong. It has done it 3 times in the last few weeks and it getting to be a concern. I have about 56,000 miles on it now. Anyone else found an answer to this. I have two friends who have the titans and are having the same thing happen occasionally. Is this a recall item?
I have a 2004 titan crew cab.