That is very true. Many people haven't bothered upgrading to Vista so it would effect sales of the Vista only Halo 2 badly, but I also think it is down to the game now being quite old and losing its appeal.

People have been moaning about staggered release schedules across different regions for many years now, and I don't think we are going to see an end to it any time soon. It's one of the things the fuels the more serious gamers to chip they systems and just download the games, rather than waiting for an eventual official release.