Need some assistance, please.

Poor Adam is stuck in the cave. If I hear Hans whine "Adam do something" one more time I will scream or made Adam drop a rock on him. Ha Ha! Anyway there are 2 beams on that boat which Adam can drop a rock on. I have tried both of them but I can never find the chain afterward. If I try to make Adam drop a second rock on a beam he states it won't work, even though the rock lights up again. Is there a glitch in my game or am I just not finding the right pixels for the chain? This sure has been one doozy of a game so far. I needed saved games to bypass 3 of the timed puzzles already, thanks Sue. But now I am stuck in that cave. Is there a proper sequence to dropping the rock on a beam? Which beam and where's the chain? Thanks for any help.
