I have two 360's. One of them was banned when COD4 came out. The second has never been modified at all.
The first had destroyed 2 of my games before I modded it, so I still play backups of non Live games on it.
The second has nearly destroyed at least one of my games that I like to play on Live and I've just discovered that it is too scratched up to install to hard drive (now that I have a 120 GB option I'm learning about this). Also of note is that the game has never once had any issues while playing.
Amazingly, I can still make a back up with it, I just can't get NXE to install it to the hard drive (always says dirty disc).
If I use a backup and install to my HD on the banned 360, then use the original disc while playing in the not-modded 360, will it get banned?