Latching motor probably cracked or stripped its gear.
When you try to use it, can you hear the motor going, but skipping? Is the cab light on the dash staying on?
I've had the top on dad's car apart a few times, and "translated" the factory manual into an easier DIY:
http://forums.pelicanparts.com/porsche-911-technical-forum/342119-cab-power-top-electrical-testing-diy.html
One thing: be very careful about using it while it is out of sync. It's *really* hard on the motors, cables etc. Will even break the roof struts if it's really out of whack
THis should probably be moved from OT