I found it does that when the PC hits an oddly encoded video.
But you are right, why would any consumer want to know this?
Bob
<span id="INSERTION_MARKER">When a user attempts to navigate their iTunes menu on Apple TV via Apple's Home Sharing, Home Sharing crashes. Some users do not experience the problem using Airtime when they navigate their iTunes menu from their PC/Macs, but the problem returns, and Home Sharing crashes again, when the user attempts to navigate their iTunes menu from their Apple TV. The problem seems to have started with the latest ATV update. Several ATV Community discussions have voiced their frustration, but no word from Apple or patches are available, yet.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic