Hi, my stain is going on tomorrow and I would like to know why solid glued & nailed 5" planks would start creaking where the boards meet widithwise. Four areas are very noticeable. They didn't start doing this until they were sanded. They are beveled, 5/8" thick walnut, a few were mismilled and were accidentally installed, so they were edged down. I think these are the areas that began creaking, after they were leveled out. What could cause this, and can top nailing or screwing them correct the problem? I don't want to deal with this after the finish goes on. If the top surface of the wood becomes too thin above the tongue, can this cause future problems? Thanks!