I'm getting a popping or sort of a clunking noise occasionally when I brake. I'm not talking about the grinding you hear from the rotors. The weird thing is that it only happens under moderate braking and usually at the same traffic lights. I'm a little worried it's my transmission since it doesn't seem to occur when I throw the car into neutral (I have an automatic). Has anyone ever experienced this before? Could it possibly be a bad strut and not the brakes?