System sounds "queued" up Occasionally, when I've had my mac on mute for a period of time (eg., several hours), and then plug in a set of headphones, I get a backlog of system sounds played to me.  (chirps, new email sounds, etc).  

These are sounds that would've/should've been played over the day, but weren't.  It seems the sounds are queued / buffered, then when I plug in my headphones, the queue is emptied.

What causes this, and how do I prevent this?
This is a bug that still exists in 10.8 unfortunately. It also randomly happens now when turning on AirPlay Mirroring so you can hear it on the big screen!

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