Has anyone managed to get Myst V to run properly under Snow Leopard?

I have managed to install it on my Mac Pro by copying the files across from a powerPC system. It starts up O.K. and I go through K'veer age and meet Yeesha. When she finishes her speech nothing happens - none of the keys work and I have to use alt/cmd/esc to exit the game.

The save file I have from the powerPC system works so I can continue where I left off previously but I would like to be able to run through the game from the beginning.

-- Geoff