I always have yeast clump up or form a krausen around fruit or other additions and on the hop bags when I use them to dry hop. What your describing sounds pretty normal to me. Fruit will start fermentation up again because of the added sugar from the fruit. Just make sure your FG is stable for a few days before you decide to package the beer. That krausen you're talking about shouldn't effect the beer flavor, but the fruit and spiced beers I've made have taken a longer time to condition. It takes a while for those extra flavors to blend well with the beer. It may be very tart at first but in time it will mellow out.