Mine was leaking last year. I think condensation on the outside. I used 2 cans of instant foam (
http://greatstuff.dow.com/greatstuff/diy/products/fireblock.htm )to insulate the boxes. Moved the stove out (without disconecting the gas, only removed the holding bar), removed the panel under it, and you can see the seam behind the refrigerator and the open space (uninsulated). Also the Airconditioning duct runs behind, and where it goes thru the divisions, used the nozzle to inject some foam. On the front of the fridge panel by the floor there was a little gap that allows the nozzle to go in and inject some foam.
On the salon side I drilled a few holes on the wood behind the cushions and injected some in there and taped the holes, but the original insulation seemed to be in good condition there.
You can also check the drain tube that goes from the bottom of the freezer to the refrigerator and then the fridge drain hose, make sure it does not leak in between, and that the hose goes to the bilge.
Marco