Brand new brake pads glaze just as easily as worn pads. It's not really a matter of how new they are it is how they are used, aftermarket brake pads are notorious for squeeking and is the main reason why I run OEM pads (their usually the same price anyway).
Did you silicone the back of the pads to the caliper piston? Doesn't always work mind you. Have you taken her out and done some real hard stops to get them hot yet?
“She may not look like much, but she's got it where it counts, kid. I've made a lot of special modifications myself.”
— Han Solo