Problem with Spirit Form

I don't seem to be able to get Spirit Form to work properly. I have tried to use it in several different spots in the game (Mithalas Cathedral, the king's skull, the trident, etc.) but every time I do, it just snaps me back to the first blue crystal and won't let me pass the gas jets. So far I have tried: starting at the first crystal and then clicking on the "7" hotkey as I reach the second one; starting as close to the gases as are safe and then clicking "7"; clicking in the middle of the space near the second crystal, etc. I have logged out and restarted the game several times and repeated my efforts again, but nothing seems to work. I'm beginning to wonder if it's a bug or a glitch in the game. I know that it is switching into Spirit Form, because when i do it in the Arnassi Ruins, I can see the racers. What am I doing wrong?