On the early boats (pre 350ish) there were issues with the beam trays (if that's what you are referring to). Later boats were re-inforced in the tray area. Separating deck/hull joins at the beam trays in later boats wasn't an issue that was at all common. The decks are bonded to the hulls via a lip that is approx 1" - 1.5" wide as part of the hull side moulding and held down with a strong resin mixed with microballoons. If a section of deck is coming off it's invariably best to remove the deck and re-stick it than to try and get a paste into the opened crack.

It sounds like you have one of the earlier boats. Post up a pic or two of the damage and we'll see if we can advise.