Jon, I know what you mean. I was shaping a piece of fancy Claro for a stock and kept hitting open "bark pits" as our local stock master called them. Most went away as I cut deeper. Then I hit the mother of all holes and it looked like this one was going to get bigger and bigger. I had bought the blank from a reputable dealer, Cecil Fredi, so I called him. He said to keep going and if it didn't go away, he'd replace the blank. I kept going and the void went away. I was lucky that time, but it was nice to have backup from the supplier.
BTW, when I first read the title of your post, I thought you were going to say the duplicator went haywire. What kind of machine are you using?
