[Franco]

I had the same problem with mine. It seems to me that it was caused when they cut the holes for the deck plates. When I fixed mine in cut those hole about a 1/4 inch larger abd glasses the edges. I might also recommend that you use a grade piece of plywood that has as many plys as possible. I happened to have a piece of 1/2" cabinet grade hardwood plywood - 7 plys -
very stiff and stable. ( I build cabinets and furniture as my other hobbies) glassed it in using west system. Works like a champ and did it all in an afternoon