I have a stange noise they are looking into now... at low speeds, when just touching the brakes, or as I come to a stop, it sounds as if there's a Pigeon under the hood - "cooing".... I also get a slight snap from the front left brake, when pushing the peddle - even if I'm already depressing the peddle, if I press down further, I get that "snap."
Very odd - I had an '06 GS as well and it never made that noise...
Lee