I have tried everything you have said to try and I still come up with the same result.
I have an Xbox Slim with a 250 GB Hard Drive (Formatted)
The game is a new Star Wars Episode III: Revenge of the Sith CD I checked the compatibility list and it is in there.
When I try to start the game the Xbox symbol shows then the error pops up, it reads:
The original Xbox game has encountered a problem:
This original Xbox game is not supported on your Xbox 360 console. An update to support this game may be available. For more info. go to www.xbox.com/games.
I have the latest update and I've tried deleting the update and updating again with no luck.
I appreciate any help you can give me and thank you.