I've had my (unlocked) 4S for a month now, and all of a sudden I got this problem - the volume buttons (+/-) on the left side only works when I have headphones plugged into it, and applications do not play sounds on notifications etc - but when someone calls / I get a message it plays sound. On Sleep Cycle and Spotify it says "No volume available" (and no the iPhone is not muted). I took it to an a store (not an Apple Store, as we don't have them in Norway) and he basically told me the buttons were broke because of moist - but why would they then be working when I use headphones? The volume buttons not working is not my biggest problem - my biggest concern is that apps dont play sounds, not on notifications either. Lock sounds etc do not work as well. What to do?