Buzzing noise when vibrating on iPhone 4S

Just got new iPhone 4S and found vibrating is quite loud and annoying ...
Noise stops when I press lower right corner ...

[@darktherapy]

The vibrate motor dislodges from its mount and is vibrating against the inside of the casing, new motors are easily available.

[@11browd]

Same prob

[@AlexAndPaolo]

I have this exact same problem. Does it mean my phone's broken? What is the danger's of it? and how could i get this fixed.

[@MilesAndSmiles21]

was anyone able to figure out the cause of this annoying noise? I have the exact same issue...of coarse my warranty is up though now!