Hey guys - i have '05 4.4i with 17k miles and this happens to me also like mc330i as posted above
From Cold start place car in drive and ease on the accelerator - X will buck slightly as you accelerate..if i ease up it stops and i increase pressure on gas it smooths out..as you increase in rpms car will shift HARD into second gear. This only occurs from cold start and goes away as the transmission warms up. i also hear a slight bang from 1st to 2nd only and when warm works ok...any opinions...thanks rob