Vibrate enabled when unplug headphones

[blandest]

If I have my phone on silent, either before or after plugging in headphones, when I unplug the headphones it changes from silent mode to vibrate mode. Is there any way to stop this happening? It occurs if I was using either doubleTwist or Play Music before unplugging. It doesn't matter if I pause the music first or just unplug. (Using Android version 4.2.2)

 

[blandest]

Sorry all. Discovered it is app related - I used Smart Volume Control. Even though I don't have any of the headphone settings enabled and my silent profile has nothing enabled relating to vibration, I found the problem stops if I stop one of its services.