That is so weird, Archie is exactly the same, and I never even thought cloth could be the culprit!!
He wakes and feeds lots during the night (I'm not sure how he is as haven't put a sposie on him at night, so maybe it's not cloth at all
) but when I had to put him to bed with no nappy on the other week due to extreme rash soreness (that's a whole other story!) he slept right through.
Also the last couple fo nights I've taken to changin him when he wakes up crying, the nappy has been damp but not really wet wet iykwim, and as soon as I've changed it he has gone straight back to sleep.