Media keys are not working on Firefox though they're working just fine on Chrome. I can pause playing media in an '''active''' tab only with space. I'm unable to use the seek back, forward and pause buttons. It's kind of annoying that I have to open the background tab where the media is playing and pause it with space or my mouse when I could simply hit the pause button while working. I've tried disabling and re-enabling media.hardwaremediakeys.enabled in about:config but nothing happened :( Thanks.