Re: Dryed-out Painted Interior Beadboard??!
Welcome to the world of wood movement. Wood generally shrinks in the dry climates of winter and swells during the damp days of summer. You don't mention if this is new bead board or old. If new it should have be stickered in the house for several weeks before installation to aclement. If new it may have also been a little green (high moisture content). Only time will tell if it closes back up.
Be sure you live your life, because you are a long time dead.-Scottish Proverb