One other possibility is that the bottom bracket bearings are misadjusted or otherwise out of whack. That gives me the feeling that I think you're trying to convey.
To check for that, shift into the small chainring with the front shifter, take the chain off of the little ring and let it rest on the BB shell. Turn the cranks by hand to see if there is resistance.
Oh, and yep, that's a freewheel.