Nokia has been consistently updating its Lumia 800 handset with firmware improvements over the last few months. If we're counting correctly then this week's update is the fourth major revision of the 800's firmware, bringing an important volume fix with it. The previous version (12070) addressed some battery charge issues, but introduced volume problems related to game play and louder than usual ringtones.
Nokia is rolling out a 12072 update to some regions this week, which addresses the volume oddities and allows the camera app to automatically detect 50Hz or 60Hz flickering using flicker reduction. We haven't been able to test and confirm either of the improvements, but Vodafone Australia has revealed that it's rolling out to Lumia 800's in that particular region right now.