Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Back Button not responding

This is my 2nd kindle after my 1st device was replaced due to malfunctioning key pads. Once again, I'm having a similar problem w/ the replacement- The back button suddenly not responding only after 4 days of ownership. My previous kindle was replaced only 6 days of ownership b/c all the buttons were suddenly stalled!!!. The tech support told me to try to re-set, but after few tries, it went back to malfunctioning mode.Since I'm starting to see a similar issue again w/this device, I'm afraid that there may be some technical glitchs with the latest generation kindle.