Thanks Mark there really isn't much to take a pic of and im not sure the camera would show it, I would have to peel it back with my hand, Its only peeled about half an inch all the way along the top of the cupboard. Oddly though its only the two corner units and not the one across the middle that joins them. I will take a pic for you but im not going back out for a week or so to give my de humidifiers a chance. I personally think and hope that its caused by condensation through 5 of us sleeping with the heating on etc.
I would look for any signs outside where the water could be getting in around that area and then if nothing obvious wait for the service. A pic would be good. I am not a great lover of damp meters as you can get a lot of false positives if not careful, especially in a caravan where there is moisture on most every surface especially when they are sitting empty