Why does the program freeze up in random places? Is there a way to continue where you left off or must I always start over?

To which program are you referring? Customer Response: I am using your Planet CNC software with a MK1USB controller importing a Vectric DXF file. Once I hit "Start" the machine operates fine until it randomly stops, the control functions gray out and I lose all control. Unplugging the USB and replugging it boots everything back up, but does not allow me to continue where it left off and makes me start the piece over. Additional Query: Are you using a Laptop, or a desktop with the controller? Did you purchase the controller from us, or planet-cnc?