Originally Posted by
kilted exile
Now, I should probably leave this to a muslim to answer. But I'll take a short stab at it anyway.
I think that the difference regarding the Qu'ran is treated a lot more seriously then the way Christians regard the Catholic Apocrypha. The Qu'ran (by the way is this the proffered spelling or is it Koran) is seen as the divine word of God/Allah and has remained unaltered since it was given to Muhammed, as such it may be considered divine(not suggesting here that muslims actively worship the Qu'ran however) in itself. No additions have been made and nothing has been deleted. This is in stark contrast to the Christian bible which contains writings of people, such as the many epistles of Paul, and whilst Christians believe these writings to be divinely inspired there is a slight but important distinction for Muslims on the matter.