You didnt add the F-Pack did you? If not Im thinking your water level may be a little low or even possibly you didnt get it stirred well? Other then that I would be much happier if that was the case. I always bump mist kists up to about 1.085 with about 3lbs of sugar in primary. It takes a little longer to ferment but IMO doesnt effect the taste much and balnces the sweetness better and also shelves much better this way.