I am having the same problem. The error SAYS Game cannot start. Download the game again. Contact
http://www.xbox.com/support. I talked to xbox support twice and none of their suggestions worked. I downloaded the backwards compatibility update from the xbox.com support site burned the file to a dvd and installed the update manually. Still won't play original xbox games that are on the compatibility list. The system I am having trouble with is an Elite. I also have an older premium system, when I put my 20gb hard drive on the elite system it will play the older games. So I think there is a software problem on the Elite hard drive. Any one know how to get updates off of the hard drive in order to reinstall them. I don't want to mod my xbox. I just want it to play my old xbox games like its supposed too.