Clarrie,
I am going thru exactly the same thing and seem to be going backward! I was up and down all night last night re-wrapping but ds(6mnths) wakes himself when unwrapped!
I have a waffle weave sleepbag on order at the baby shop and am going to try it - but it's Beaus arms that are the problem so I am not sure how this will help....I feel your pain!
The only was he stays asleep is if I do a lycra wrap first and a muslin one over the top again but it is way too hot for that now...i have been trying all sorts of things too - ket us know if you have any success?