I've tried hitting the lock, it won't lock during calls. It'll cause the screen to go black, then it comes right back up. Even when the screen is "black" and I've got the phone to my ear, it still opens up apps. I'm sick of my phone constantly trying to do something else like open a browser, ending calls, calling someone else, texting random people and so on. How do you actually "LOCK" the touchscreen during calls?