Hmm.. That's curious. You *should* be able to either PUSH BUTTON, PRESS BUTTON, USE BUTTON, DESCEND, D, GO DOWN, or DOWN. AARGH, I just checked and there's a small bug with a boolean which would stop you winning.
I have resolved the problem and created a way for you to get back to where you were:
restart your game, and then type "debug julia" at the prompt. The game will reset to your current location and state (with some prompts).
Let me know if that gets you going again..