I got so pissed off with my brakes squeeking exactly as you mentioned and in the end after changing pads, roughing up the disks etc and bought a can of "De-squeek" made by CBC or whatever as a last resort , cost me $20, didnt expect it to work, sprayed it on both sides of the disk, did a few brake runs (like you do to bed pads in) and it was silent for a while. Im not sure if it effects how good your brakes are but i know mine still work pretty well if i heat them up (ultimates). They will start to squeek again after a while but if you just apply a little whenever they start again (think i probably did it about 5 times and i half assed it with the wheels on) , i think it builds up a sort of light film and i havent applied any in ages. They still randomly squeek now and then but its waaaaaay better than they were. $20, give it a try