I have DP Race pads in there now.. They're barely worn. I'll check the backing plates this weekend to see if they're warped at all, but I'm guessing if they are warping, it's only after they're heated.
I also found on the wera board some people talking about the brake lever causing it. I realized that when I put my lever on, it compresses the piston a little bit. I took the lever off, and ground down the side of the lever by the brake light switch (brake lights??) to keep pressure off of the master cylinder piston.
I'll report back in a few days :)
Thanks for the help!