Of all the interesting things in Microsoft's Spring update perhaps the one that sticks out like a sore thumb is 'Improved recognition of Xbox 360 Game discs' . A friend has applied this update with xtreme.bin on his DVD-ROM and tells me that:
1.
He can no longer play his backup discs.

2. He can still play original discs.
3. He can still play on live.
He's pretty miffed all his backups don't work anymore but we figure it's a cat and mouse game now .... that or Devil360 will release their 'unsigned code' modchip and he'll be able to play them again soon .......... finger's crossed!
Worthy of note is that if I put my key and xtreme.bin on his drive and put it in my 360 it will play the backups just fine. So I guess this dashboard actually queries the game disc and tells it's a copy, then prevents it from starting.