car not moving when in shifted in reverse!
 

Hey everyone. Yet another problem...
This morning when I was pulling out of my parking spot I shifted to reverse (automatic shift), expecting the car to move, but it didn't budge. With the pedal, it started moving, but it sounded like something was stuck (a dragging noise). I shifted to D and went forward a little bit and that cleared the problem, whatever it was, as it now moves normally (i.e. with no pedal needed) both in drive and in reverse.
As some of you are aware, I posted about running over something that ripped through the plastic engine splash guards on the bottom, i'm wondering if one of those plastic pieces got stuck somewhere?
Another possibility, it was a pretty cold night last night, probably one of the coldest this year so far, and it rained so it's possible something might've frozen somewhere? I have a 2001 Protege, automatic shift.
Thanks for any input.

Just trying a theory out, you didnt happen to have the e-brake engaged at all did you? Sometimes even with it pulled just one click it can grab enough to stop the creep even in reverse, then when you applied throttle it overcame that initial grip, then when you tried it again the cable had been losened up enough to not catch again at that weak of a setting. dont know what else it could be, unless some plastic was acting as a wheel stop. check your tranny fluid to make sure there isnt grit/metal in it.