I'm sure this question has been answered before but I couldn't find it. We have two stubborn cracks, one on either side of our fireplace. The house is three years old and has skim coat plaster. These cracks are driving me nuts. I have lost track of the times I have filled them but the darn things just open up again. I have widened them and filled with plaster, tried joint compound, used caulking compound, spackle (so-called One Time), and this last time a combination of no-shrink latex caulk covered with joint compound. Each time I have painted the cracks and hoped fruitlessly for the best. What the heck more can I do short of wallpapering which I really don't want but probably will have to resort to. Thanks for any advice.