I have been programming mainly 2D for a couple of years now. For the past couple of months i have been programming and running more complex aluminum parts. Every once in awhile when i use Dynamic Optirough on mastercam x9 I run into this annoying problem where my cnc decides to randomly and unpredictably finish an arc and come full circle and then continue on its original programmed root. I have verified my g-codes over and over and i see no problem.