The recent title update to Halo: Reach has rendered unplayable the free disc version of the game given to Xbox Live dashboard beta participants earlier this year. Rather than say tough luck, Microsoft is giving all of them a free digital copy of the game.
An email to dashboard beta participants today advised them of the title update's problem and the solution. All save files from the previous version of the game is portable to the digital one.
Of course, this means one needs a hard drive with 6.6 gigabytes free, whether that's on the console or a USB drive.
If this situation affects you and you have the hard drive space, just download the digital version of the game and chuck the disc in the trash.
[h/t reader progame13]