I have a problem with my 4S in that when the screen goes dark in sleep mode it will no longer register an incoming call or text. What i mean is that i can't get a ring or text tone when the screen is blank. As long as the backlight is on like if im doing something on the phone when a call or text comes thru it operates normally. When it is in energy saver tho, and someone calls they just go straight to voicemail. This just started yesterday and the last thing i did before this happened is i uploaded my pics to my laptop from it. This is something i have never done before and may simply be a coincidence. I have read many complaints about speakers/volume not working but this isnt the same issue. Any thoughts or suggestions?