I didnt want to add this to the "ATTENTION.." thread because I didnt want to clutter it up since I am not doing the test. Some history...
I was banned on a second xbox recently. I had heard all of the theories but decided before I went out and bought another xbox or hard drive, I would test for myself. I actually expected to be banned again due to using the same larger hard drive I used before even with a new eeprom. I was.
I think you all are close to having confirmation on what they are banning for. My concern is that they may be able to somehow detect a large hard drive in other ways than just the serial number. I know the eeprom and the hard drive has to match and this is why I think I was originally banned.
I am going to consider getting a box just for live and a new gamer tag. I hate it because I assume I will have to start a completely new account?