Just in case anyone else wanders into this difficulty, I think I may have found a solution to this glitch.
I had the exact same trouble, and I tried restarting 2-3 times from a save right before going into the secret Academy, with the same thing happening every time.
Eventually I came to realize that my characters should not be staying in the entranceway, they should be imprisoned. I concluded it must have been an error with a trigger or script.
I realized that each time I chose to simply lay down my weapons at the first opportunity.
Restarting the level again, I chose to delay that option by choosing to tell them that they'd have to make me give up the weapons. Some dialogue with Kreia that I hadn't heard before occured, and, boom, the wind up in the cells.
It's a forfeit of some lightside points for the ability to continue the game.