I am in the gem mines and have doused all the Ghost Lights, killed all the baddies and made 3 full run throughs, but none of the ghosts (except the Librarian) will allow to be guided to the Tree Room.
What is missing?

You don't actually guide them. I found that I could only do one at a time. I'd 'nudge' him from behind and he'd run close to the next set of ghost lights and wait. I'd turn the ones -behind- us back on and then turn off the set in front of us. Rinse and repeat until he gets into the room with the tree. The trick on the big room just -before- that is to make sure that the ghost lights are ON in the doorways leading out. Otherwise the dumb bunnies run back out again. :P

OMG, what a silly thing! Thank you for the info. I was under the assumption there was a problem of a higher order, not something where we become Ghost Herders!
Thanks again!
JD

You're most welcome but...did it work all right? ;)