Bcolor

I recently got myself a 2006 F150 automatic 5.4 4X4 XLT with only 85000 miles and iv noticed a possible shifting error. while i'm accelerating the RPMs drop slightly while im in second gear around 2500 RPMs before it shifts to third. it does it again in third before it actually shifts into to 4th. i do not notice a loss in power when it does this and my acceleration still feels smoth. but when i get on the gas this does not happen and it shifts through all 4 gears just fine with out the RPMs dropping halfway through the gears. at a steady speed it does not have any problems and idles smooth. is this something ford did to improve gas millage or is it an actual problem? Please help

History: purchased truck with 80000 miles on it. Ford dealership did some maintenance prior it me buying it to fix an engine surging problem. changed spark plugs and replaced 2 fuel injectors. claimed problem was fixed. havent noticed any surging sense.