The condition sounds similar to a problem that I had with my wife's contour (97GL). At a stop in drive, the car would shake and rough idle. The wheel would shake mildly, and it would drive me crazy so much that I would put the car in neutral at a stop. In my case, changing the timing belt and timing belt tensioner fixed the problem. The mechanic told me that it was actually the tensioner (bearing was shot), but it made sense to replace both considering I was at 70K miles.
Good luck.