Put a brick through it?
Seriously though, it sounds like a cable on that side either snapped or jammed up on something.
Have you tried assisting it in opening with your hands? You may be able to dislodge it, but be careful, it's better to have a closed sunroof on a hot day than an open one on a rainy night.
My Jeep is a chick magnet with reverse polarity.
Rampant Pack of Retards group president.
2000 WJ, 4.5l, AX15, 242 D60/14b, 5.5" lift front, 7.5" rear. Ford Expedition rear coils, Ram 350 shocks, JKS, IRO Long Arms, cool Badlands flag thingy.
1987 XJ - Gone but not forgotten