My guess is you have about 20k to 25k miles on the car. Replace the spark plugs and it will fix it right up. I'm on my second e90 and both have had this behavior, especially when cold. It got worse until around 30k miles when the plugs were replaced. After that it was fine.
Dinan compliment of stuff plus PF rotors and RG63s. Enough for now.
Why, yes. I am an abrasive bastard.