Justin Marshall

when I first bought the car there was a code for the throttle position sensor which I replaced. From day 1 the revs jump when shifting almost like its slipping, but only when the engine is cold. when the engine is warmed up it shifts like butter. I did a drain and fill with honda atf a few weeks back with no improvement. Here's the kicker: with the engine cold if i engage the cruise control it shifts smoothly which is leading me to belive that it may be something other than the transmission. Any ideas? Auto transmission with 150k miles