There was a bug in the Amicron Video Player that was preventing the handbooks from loading for some customers. It was working fine on my system, but then a customer complained that she could see them in the course list, but nothing happened when she tried to run them.
So, apparently it's only a problem with different versions of Acrobat Reader. No big deal though - I fixed it. The latest version of the Player will have the fix. When you load up your Player, it should show that an update is available. Just click and run the auto-update and you'll be all set - or you can download it again from the Downloads page.