I have a 10 year old home (which I built myself ) and now I have the nails on the out side ONLY walls showing through the paint on the drywall. (this suggests to me that maybe because the wall is colder through the winter it's discoloring.) they're NOT nail pops! just discoloration that approximates the nail head size... you can see EVERY nail where there is paint.. the wallpapered areas DON'T show through.... some areas have been repainted and after a short while (maybe a year) we start to notice the nails again. the walls that have the problem are 2x6 walls with R20 insulation and a 6 mil vapor barrier.. any suggestions?