Is the rotor rubbing one pad constantly and staying heated up? Absolutely no oil or cleaners getting on your rotors when you clean it after rides? Just a little over spray of some cleaner or preservative might let it squeal.
How much did you pay for your L03A pads? I haven't put pads on my cars for less than 80 bucks a set for a long while, recently over 100, just for the pads. My L03A's were about 30 bucks or a tad less IIRC.