Transmission bounces between 2 to 3 gear

Crown Victoria 1996 4.7L 85000mi (140000KM )
I had my transmission completely rebuilt last year (nov08) and recently there is a problem when the transmission shift from 2 gear to third gear, there is a bouncing action. (Spring reaction)

(hard to explain here, but its like the RPM is accelerate, when transmission leave the second gear et release when the transmission reach the third gear)

I show the problem to my transmission rebuiltder and they said, its not a transmission problem but a PCM (Power Train Module) problem. (maybe Lock-up shifting problem) They want me to check if there was a recall from ford about reprogramming the PCM !!!
Somebody know what I am talking about???

i'm not sure what the problem is, but my 95 does the same thing, feels like something grinds when it comes out of second until it gets into 3rd, only for about a second or 2 but for some reason it doesn't to it all the time, only when it feels like it i guess, might just mean its about to go bad...whatever "it" is...