PAL gamers: a note on switching between 60 Hz and 50 Hz mode in the Xbox’s dashboard settings.
If you decide to switch between the two TV standards, then take heed that by doing so, the Xbox will reset all your game data for Halo 2. So, even if you resume playing from a saved checkpoint you will start from the beginning of the level regardless!
Consequently, let’s say you’re TV mode is set at the default value of 50 Hz, and you switched it to 60Hz and commence playing Halo 2; your saved checkpoint from the 50 Hz will be lost. However you can recover it as long as you do not save on the new TV mode, in this case the 60 Hz mode. Otherwise you’ll have to start all over. So turn off the Xbox instead, rather than using the Quit and Save feature.