The Halo 2 Autoupdate is a small piece of software which will improve the functionality of Halo 2, most notably in the following areas:
Matchmaking: Some players have experienced irritating delays while waiting for a game to be found while in Quickmatch and Optimatch. This is caused by a combination of factors, including connection speed and other detailed nuances of matchmaking. We have isolated the cause and applied a solution to the autoupdate which should normalize that wait time.
480p Support: The autoupdate will improve support for 480p resolutions on a wide range of HDTV and EDTV displays, correcting a flaw that the software encountered with some sets causing part of the HUD to be obscured. This problem does not currently occur on all HDTV sets, so it is possible that your specific set is unaffected right now and it will therefore not be altered or changed by this autoupdate. If you are seeing the HUD clip or bleed off the screen in 480p widescreen and 4:3 modes) this should address that problem perfectly.