There is a very annoying creaking noise which has kept occupants of both rear cabins awake when rolling at anchor even in very calm conditions. I think this is coming from the bulkhead at the rear of the engine compartment, back of wardrobe, and under the bed, I could see adjoining pieces of wood moving relative to each other, which I secured with additional screws, however I think this just moved the creak somewhere else. Anyone have any experience in eradicating this problem?