Ford Repair: jerking and missing, downshifting, 2006 f 150

Question
I have a 2006 F-150 with less that 19,000 miles I bought it new in 2006 so it's still in warranty. Sometimes at idle it will seem to miss. Also when going about 40-50 mph up a slight grade, or when taking off from a stop, the truck will start jerking hard, like it's the transmission, but it could be the engine. If I let up on the gas and accelerate slowly, it will stop jerking. I took it to the dealership and the said they couldn't find anything other that a service bulletin regarding hesitation on downshifting and the reprogrammed the pcm. However, it's still doing it. Do you have any ideas before I take it back to the dealership?

Answer
The idea I have is to tell them to fix the truck. Hey, I know how that works on both ends. Just tell them that the truck scares the crap out of you and you don't want to have to keep coming down there. Tell them to give you a rental car and not to call you until it's fixed.