Why can't i hear my nokia lumia 625 at top volume even when it's in my pocket?

[WPCentral Question]

My Nokia Lumia 625 May as well be just a camera. It's Loud enough when it's sitting on the table, but if I have it in my bag or pocket , i can hardly feel the vibration & can't hear any ring tone. Missed almost every call since I got it
Please Help Fay.

 

[Muessig]

Honestly I've had different strength vibrations with different updates. What firmware are you on? I'm on the 8.1 Update 1 preview and I've noticed the vibration strength on my phone is improved.