We recently did a comprehensive remodel of our very old condominium. Its a four unit row house from the 1890's. I noticed that there is a long crack going up the corner of a back room. Is this a common thing when a new coat of compound and paint is applied? Or is the building settling because of the cold weather, or is there a major structural issue? I'm noticing a similar thing with the grout in the floor / wall corner of the bathroom. Kind of cracking an separating a bit. Any ideas?