They are not all listed but it is believed 1 or 2 cut scene's maybe linked to a time related bug that is in the process of being released as soon as Microsoft test it.
In short it has been found that if you take around 70 hours which includes pause time then such a bug may show up. Many people have played the game much quicker then my self and have been ok so for them it is not broken.
Here is the full topic, look for posts with Larian Studios to get some answers for now.
Post found under Technical problems:
XBOX 360: Sassan can't summon demon.This should point you in the right direction until guys from Larian Studios can get a look. If you can't wait for the patch then you could start again, be a little quicker, save and exit game if you are away from your screen for a long while ect... Maybe you have an early save you can fall back too that will allow you to be quicker?
regards.