Nokia Lumia :: 920 - No Ringtone When On Vibration?

I have a US ATT White Lumia 920. Here are the steps to replicate the problem:

1. Switch phone to vibrate only: Press the volume rocker and hit the bell on top right to switch the phone in to vibrate only mode. 2. Play music on phone: Plugin headphones or play music on the phone speaker through any music app. 3. Call your phone from another phone.

Expected Behavior: As with any phone when you play music on the phone and get a call, the phone should pause/stop the music and play your ringtone/ caller tone. After the call has ended the music should continue.

Issue/Bug: The phone does not pause/stop the playing music when a call comes. However the phone does vibrate. This is a problem and has lead to missed calls when the phone is in my jacket pocket or bag where the vibration cannot be felt.