riven-stuck again

thanks to a reminder from dee. i got out of the last fix i was in very nicely. now i am in age 233, the room with the cage and the linking books to the 5 islands. i have the red light in the powering generator glowing. when i click on any of the linking books, i get a picture of the rotating sphere on an island, the hand comes up, click on it, then it tells you to change disks. then another book comes up- it is always the book to the 233rd age again, then change back to disk 5, ect. cant seem to get out of this place-is there a trick to it? what haven't i done?
thoroughly stumped.

When you arrive at Prison Island mamma, back away from the book and note the button on the floor. If you click on the book, you'll just go back where you came from.