I have read your posts and gone back and had a very close inspection of the quilt and the problem.
All the stitching is intact except for the ends where I brought it through to the back and tied them off. I am beginning to suspect that the knots have come undone somehow.
So what I intend doing is as you suggested paperprincess and that is re -quilt the ends and make sure that I do a very small backstitch and when pulling the threads through to the back that I will tie them 3 times instead of twice and leave longer tails to thread back through the wadding.
As for washing the quilt I put it in my machine - which has a big wash bowl - with a couple of colour catchers and just put it on a very gentle cycle. I did not let it go to spin I took it out with the help of hubby and put in on the line where it was given a good hose down to remove any suds and being a windy hot day it was dry by late afternoon. The washing result I was very happy with - it came out looking just like new - no crinkles, no colour runs - I always pre-wash my fabrics to start with - or shrinkage. Just the ends came undone.