Auto trans shifting all the time at 45 miles an hour... what could cause this???

Yep,Mine did the same thing, I first did Michael's 4th gear hunt fix. Worked great for almost a 1/2 a year or so. When it came back, I had to take it to the dealer & they reflaswhed all my onboard computers, mine had the original factory settings. Works great now, even has way more power than before while it was running fine. I can smoke my dually tires now if I want on a stock truck.The Chrysler Dodge dealer charged me $132 & change for a full fuel system check, saftey check,2 test drives & to reflash the computers.M73M did point out that there was a factory service bulletin on this problem & sent me the link for the fix!Dave