Are you sure it was smoke and not steam? Mine steams like a boat on cold morning, it goes away after a few km.
Make sure you measure the oil level in the exact same conditions - same place, same interval after turning off the engine. The oil indicator on mine has dropped one line after like 1000 km (but didn't do it before, after 2500 km) and the consensus around here (see my thread about the trustworthiness of the sensor) is that it's rather unreliable. I've had it displaying anywhere between 3 and 6 lines and the level on the dipstick was always at the maximum. The indicator is also sensitive to the position of the car, i.e. how close to the horizontal it has been parked.
As yours is still under warranty, I'd go and get it checked. Mine is not, so if it breaks, it breaks and gets fixed.