Yes, but I've become adept at knowing when it's not fully engaged in 1st. It's not that it's popping out of 1st gear, it's that it hasn't fully engaged 1st gear. It's gotten a lot better with time and I only have 2400 miles on the car. To the point where it hardly every happens but when it does it's usually always cold and always in a parking or moving around the driveway. Once it's on the road and warms up I cant recall that last time I had it happen at a stop or a light.
As much as people will argue with me I chalk it up to it being "the nature of the beast", as in, "It's normal". Every one of my manual sports car, and I've had over 20, has certain mechanical characteristics that make them unique. A lot of times it's not something a lot of others have or better yet, notice they have but every one of them has something that you need to adapt to. This is one of those items. It's certainly nothing I would want the dealer tearing into the car to try and fix and something that has absolutely no bearing on my enjoyment of the car.