Brandon, what exactly is "Smart ForTwo infamous dive" ?
Don't forget, the gearbox "learns" how you drive, so if you tend to push a bit harder (so it stays in gear longer before changing up) it will try and do this more often.
I have a really simple rule with my auto box. If I'm driving normally it stays in normal mode (even if the car is in sport). If I want to have a bit of fun it goes into sport, and back lanes & Milton Keynes get the full manual treatment.
In almost 8k, the car has been faultless engine/gearbox wise. It does what it should when it should. The only thing I wish is that it changed down a bit earlier in normal mode as I like to have engine breaking, but I just over-ride it on the paddles.