I just posted about this, urging people to take their door panels off while they DON'T have a problem, and to 1) lube, and 2) tighten things up to help PREVENT such a problem.

In my case, sort of the same thing. Suddenly, whammo! The window went down. When I took off the door panel, I had to figure out how to get things out, and put it back together. I too, thought it was the regular, figured some teeth were bad.

Turns out all the teeth were fine, but the lubing was dry. So I scraped off all the old grease, put on all new everywhere I could. Putting that stuff back in is a real bit*ch! Much easier if you have to people, someone to put the window up/down so you can watch to see what's going on. TAKE MY ADVICE. Take off the other door panel too and watch that, so you can see how things come off, and go back together. I don't know if you can see or feel all your teeth on the regulator, but if they're ok, DO NOT DISASSEMBLE everything. You're much better off if you can leave things in, lube them, tighten up screws. Big hassle to get that stuff out, and back on.

Good luck.