Have you checked this:
Look under the car by the front driver's side wheel and look up. There are two "boxes" one white and one up above that is black.
There is supposed to be a bushing that fits around the "peg" sticking out in the picture (white box).
My kid had the same problem with her Contour. The bushing was still there but it was distorted, she replaced just the bushing and all was fine. Ours was missing (as seen in the picture) but I had no problems shifting at all.
The part was $13 and change at the dealership.
Not sure if that is your problem but it's worth a look see.
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