The above poster is right, you should have a good warranty. My last one had these issues, and they are fixable. They had me take it back three times, two different things in the transmission are responsible for your issues.
Last time. it wouldn't cause me probs until after driving nearly 100 miles on a hot day...but these are serviceable. If you don't have the bulletins, a Ford dealership should be able to fix you up, and it should be covered by warranty.
Made a tremendous difference when fixed!