That's on a laptop I installed Jessie on today. In XFCE 4 (no reason to believe it is specific to that desktop interface), when I pressed mute key (F7), indeed the sound goes off. But afer that, pressing again F7 did not unmute, nor Volume up or down key.
When I have gone in Mixer application, I saw that Mute was muting Main and Speaker Channel. Unmute was unmuting Main channel, but leaving Speaker channel muted. Manually unmuting Speaker works, giving back the sound. I looked in Parameters/Keyboard, then look at keyboard settings, but there was no F7 key (or F8 key for up or down volume). I have seen that list-acpi, was showing the event... but I don't really understand where the actions are taken. I even do have visual feedback when doing volume up or down on the screen. But somehow would like to fix the unmute, not unmuting speaker channel and don't know where to look.
