iPhone 4s BUG: no sound, no vibration, works 2 sec after a restart and then stops...

Hi - my iPhone 4s got exchanged 1 month ago for a new one as it was not working properly.

I'm afraid the new one is even worse:

SYMPTOMS: I basically got no sound: I cannot listen to music, cannot hear anyone and people do not hear me if I make a phonecall, vibration doesn't work either (if I move the silent switch no vibration happens, but I see the silent icon changing), and earphones connected to the jack don't output sound either. Basically, the iPhone is 100% mute.

WHAT I TRIED: reset settings, hard reset, full restore, cleaning the dock area - nothing works.

DIAGNOSTIC: After losing hours browsing the web I figured the most common issue is the iPhone is thinking it's docked. I don't think it's the problem as the docking area is super clean (the iPhone is 1 month old). I did try to clean it with compressed air, and I tried to dock it also ... but no luck.

I think it's not hardware but that there is a real stupid bug in IOS. The reason I think this is: when this problem first appeared, a simple turn-off/on of the phone would bring it back to life. But since I reset the settings (on Apple's recommendation, thanks ...) this trick (turn off/on) doesn't work any longer. But - in the current situation, when I shut it off/on, I can make one phonecall (i.e., the microphone and the earphone speaker both work) but then, as soon as the phone attemps to use the music speaker, or if I move the silent switch, it stops working and goes back to being completely mute.

Please make sure to correct this bug in the next IOS update.

Thanks.

Emmanuel