I was forced to play the game on the older white Xbox 360 model for the first few days of buying the game. There was a huge amount of issues that kept cropping up whilst I was playing on this model. One of the main issues was that while I was carrying a spell in my hand, the little graphic that represents the spell (fire animation for flames spells ect..) did not appear. I would walk around with invisible spells in my hands! I had to re-equip the spell for the animation to return.
Another problem that kept cropping up was the game not fully loading the textures right away.
However, I now play the game on a new Xbox 360 slim and the game runs perfectly with hardly any issues (Apart from the odd bug here or there)
I don't know if that information was useful to anyone but I thought I'd share. I am just glad I don't have to use the older machine anymore.