It's true that the home button is for going to the home screen, but that shouldn't be what it does when the screen is off. It should turn the screen on, then go to the home screen when it's pressed again. That's how it has been on stock ROMs, AOSP 4.1, 4.2 and 4.3 ROMs (including SlimSaber 4.3).i'm not sure if that is the right behavior for home button because home button is intended to go to home screen. i know in your situation is not desired.