I've tried everything that has been suggested here to make my front brakes stop squealing. I've greased the backs of the pads, tried different combinations of pads and rotors including OEM and Zimmerman rotors, and OEM, PBR deluxe, and Mintex pads. I am currently running with the Zimmerman cross drilled rotors and Mintex pads (a combination recomended by FCP Groton) and the squealing is worse than ever. The only part in the braking system that is not new are the calipers. Since these are basically hydraulic pistons and subject to internal wear, is it possible that vibration from braking is causing a squealing from the calipers? This is the last thing before the car goes into the classifieds which I don't want to do because the car is excellent mechanically and cosmetically but this progressively worse brake squealing has gotten bad enough to consider geting rid of the car.
Just wanted to bounce this caliper theory off some others before replacing them. Please let me know what you think.

Thanks,
Jim