I went back and measured the indents. They run from 1/64 to 1/32 inches, which fooled me, they look worse and from 6 to 10 inches long, . All the indents are running along the line where the tapered ends meet the straight pieces, on the sides that I planed to a taper. I tried for a tight fit on these joints. It looks to me like the glue joint failed. I used Titebond II. I still would like to know for sure what happened.