Nice versatile add-on. Here is a bug newly appeared: when other tab is activated, a mini player shows up on that tab to continue playing the YT media, once the YT media tab is closed without pausing it first, then the mini player can never closed anymore unless you restart the Firefox, and the more YT playing media tab you close in this way, the more mini players will remain unclosed in the same manner. Hope this will be fixed soon. Thanks.