I'm pretty sure it has nothing to do with the type of 360 since you have a glitch on your 250 GB slim while I have the same glitch on my 20 GB fatass. I've also tried different resolutions and nothing works.
Also, the key you're refering to unlocks the chest on top of the stars but since it's possible to pick it without the key you might end up with a key you don't have a use for. Same thing happened to me. That's hardly the reason for the glitch.
Is anything supposed to happen if you try "using" the soul forge book? Can you read it? If I "use" it I end up exiting the inventory but nothing happens. Is it supposed to be like this? I do remember trying to open it before talking to Sassan.
