If a wood-frame building, they sound like normal settling cracks. During the season changes the wood settles, causing small cracks in the texture at the wallboard joints and in the paint. If they installed the wallboard with a joint directly above the window or door jamb improperly, a crack will show there. If the cracks are in a straight line, it's a joint. If crooked, and not plaster walls, I would be concerned. Be safe, GBAR