I have an '04 GTO with the auto tranny and have not yet experienced this problem. I did, however, experience the transmission appearing to not downshift properly when I nailed it at about 40 mph on several occasions. I think that it only downshifted from 4th to 3rd instead of dropping down to 2nd. I any case, it was very sluggish until the engine RPMS got back up again. Yesterday, however, I did the same thing and the car downshifted aggressively and took off like a bullet from 40 mph (like it's supposed to). Maybe the computer is still "breaking in" and learning my driving habits? I don't know, but it does worry me to hear about you problem. I've only got about 500 miles on the car at this point and I'll be watching it closely.