Transmission issue, has anyone experienced this before?

[peter04330]

Hey everyone, I just picked up a sweet 04 330i Sport, Performance, "M" edition in Imola Red. The car is just broken in with only 30k miles and all warranties in force. NICE!!!
I am however experiencing something with my transmission which I had not seen in my previous 330i. And this CAN'T be right, even though two dealers have told me, "well, there's no fault code so there is no problem with your transmission"
Can anyone help or diagnose?
It has only happened three times so far but I'll be driving in "Drive" setting, not 'Sport", just driving along casually when I start comming down a hill going about 50mph, lightly apply the breaks, next thing I know is the car downshifts like a son of a bitch and runs the rpm's up to 5,500. I'm like "shit" W.T.F.??? So I let off the break, still won't shift up. So I gas it, up to 6,000 rpm, let go of the throttle and it still won't up shift... So I then push the shifter over to 'Sport", then back to "Drive" and it finally up shifts. Good thing I wasn't on an icy mountain road mid turn A? This has happened two or three more times. I'ts like the transmission thinks I am in Sport mode but I'm not. I'm in "Drive" No fault codes or lights come on. It sounds like either a software issue or something??? Anyone???