I took my panel off and everything is in tact. How I hear it, it appears that the there is not enough ' energy' if you will, to push the window back up.
Since the motor sill runs, I think it does sound like the regulator.
http://www.fuzzycats.com has a how-to for a similar situation.
I just now have to find a good deal on a regulator because I don't want to buy an expensive OEM regulator.