We have a house that was built in the 1950's with plaster walls. About 4 months after we moved in we noticed the paint on the family room walls was starting to crack and peel. It's happening on all 4 walls, not just in one area. The paint underneath it is a shiny copper color. Could this be due to the type of paint that the previous owners painted over or something else? We don't want to repaint only to have the same problem occur again.