How do I save my meta-game score in Halo 3 Campaign? Everytime I save and quit, and load it again, THE SCORE IS OFF! Does anyone know how to solve this?

I notice games like Bioshock and Assassins Creed now say Platinum Hits on the front of the case…it makes it pretty ugly looking, but Platinum hits are supposed to be cheaper right? Is there any difference between the original game and the Platinum hit version besides that price?

I have an original xbox, and walmart sells xbox live cards for 360s. Will these work for my old xbox?