Hi there , i read everyone's comment and i also had been experiencing the same problem for a month now. Finally i have been able to find a way to fix the palm touch to pause/mute feature. Kindly follow these steps and you should be definitely be able to resolve this problem. SO here are the following troubleshooting steps that you need to follow :
1) Perform a soft reset of your device:
Now what a soft reset does it , it doesn't wipe out any data on your phone , all it does is just fixes some bugs in the internal software and gets back your phone to function normally. To soft reset the phone press and hold the power button as long as the screen goes blank and it comes up. Now, you have performed a soft reset and your phone will power down and power up like a restart procedure.
2) Now go to settings -------- motion and enable the motion feature and play a song in the stock music player. Now to pause the song ensure that the palm area of you phone actually touches the any part of screen which means that it makes contact with the screen. Please don't keep hovering over the screen or proximity sensor as it has got nothing to do with the working of this feature. Once you have mastered the correct way of making contact with your palm you would see the music getting paused on the phone.
I am sure this would help many. If you guys have any question or having any problems in fixing this feature , do comment and I would get back with relevant answers as soon as possible. Thanks cheers !!!!!!!!!!