I have almost the same problem,
When I pulled the door panel off, I found that one of the (almost) square plasitc pieces that attaches the regulator to the metal guides, was broken, plus the right side window track was ditached on the bottom screw,
So I re-attached the window track, replaced the plastic piece and when i rent to roll up the window it jammed again, and broke that plastic peice.
Any ideas of what is going on??
the regulator doesnt have much play in it,and I thought i was on the track...
what else could be jamming it?