capacitive buttons not working

[WPCentral Question]

hi,
i am using luma 720 since january 14. its good all the time. but suddenly it got problem, capacitive key stopped working properly even stop at the first time.. i have reset it via soft and hard reset. although its working but twice aout of 5 attempts.. i dont know, whats the wrong. do you plz help me.... i love my phone... plz plz

 

[anon(7900571)]

Is your lumia 720 running windows phone 8.1 developer preview or windows phone 8.1GDR3/black update ?