It's perhaps specifically a problem with YouTube, or the JS events for the video playback, or something related to that: https://bugzilla.mozilla.org/show_bug.

It's perhaps specifically a problem with YouTube, or the JS events for the video playback, or something related to that: https://bugzilla.mozilla.org/show_bug.cgi?id=1163327 https://bugzilla.mozilla.org/show_bug.cgi?id=1163327 Oh well, I'll just use a bookmarklet/AppleScript to open YouTube videos in VLC, if is too sluggish (VLC supports YouTube URLs via menu item Open Network…).