QUOTE(m1nd @ Dec 30 2007, 09:35 PM)

Well, put it this way; the console was fine and playing backups. my brother puts this game in - updates the system and next time i put in a back up game it doesn't work - i try all my other games - still no dice.
I put an original game in and it works just fine.
How can I test to see if the firmware is still modded?
You don't need to do that. It is still modded. Microsoft cant flash the drive from the console. Cant happen that way. Unless they took your 360 apart and re flashed your drive without you looking.