EDIT: Correction, PS Touch and Osmos HD are both also now failing to install, same thing.
EDIT 2: The last two apps installed fine now. Surgeon Simulator downloaded 230MB or whatever it was and failed out. Now, it only downloads 10.34MB and returns error -15, as well as "invalid resource URI".
EDIT 3: Through logcat sleuthing and rapid refreshing of files, I've figured out that it's not specifically PadFone that's doing this. It's just not downloading the complete APK to the device.
EDIT 4: DOWNGRADING to a much OLDER Play Store version resolves it. WTF?