So, I was having this issue with Rythymbox. Whenever I ran Rythymbox, my keyboard would stop working and as soon as I quit Rythymbox, it would work again. I had no idea what was causing the problem. I thought it was some bug in rythymbox and updates will fix it, but it didn’t. I searched the forums for days with no success. Fortunately, days later I found a solution in the fourms. Some other user had a similar problem and he wrote that disabling the LIRC plugin in Rythymbox solved it for him. The problem is not with the LIRC plugin though. It occurs because of bad configuration of LIRC. Since I was unable to configure LIRC for my HP Remote Control, I knew what was causing the problem. So, I went ahead and disabled LIRC plugin in Rythymbox and also removed LIRC by typing
sudo apt-get remove lirc
in the terminal. And this solved my problem. Hope this helps those who are facing similar issues.