Have been enjoying picking this game up again, but I seem to have found a bug on the weight guessing game.

I pick up the dumb bell, get the magician to make it invisible, then run to the weight guessing machine and jump on. But the scale just repeats the cycling through numbers animation for ages, until the dumbbell becomes visible again and then gives me the weight of the character plus the dumbbell.

The weight machine will also not show the weight of the individual characters, will only show the weight when the character steps on with an item. When stepped on with no item it just spins forever.

Am I getting something really wrong with this puzzle or is there a bug?