My S4 will freeze occassionally. Usually when I try to wake it up...either with the home button, or the power button. It will freeze at my lock screen or home screen for about 10-15 seconds so I can't use the touchpad. I can turn the screen off and on, but I can't swipe, touch apps, or enter my passcode. Has anyone else had a similar problem with their S4? If so, any tips?