Apple has been released iOS 4.2.2 ipsw firmware for Apple TV 2G specially to fix a lot of bugs, check out full changelog for iOS 4.2.2 after the Break.
iOS 4.2.2 full changelog:
Audio
Addresses an issue in which audio is not output when playing some video content.
Video playback
Addresses an issue in which video is not displayed when playing some content.
Audio output setting
Adds an audio output setting for switching to 16-bit audio for compatibility with some TVs and AV receivers.
Live FF/RW improvements
Improves the performance of fast-forwarding and rewinding live events.
Movie description
Addresses an issue in which the description information is not displayed for some movies.
YouTube video order
Addresses an issue in which YouTube subscription videos were not ordered by date.
Download iOS 4.2.2 (4.3) ipsw firmware for Apple TV 2G
 iPSW Firmware For Apple TV 2G){kind=link}