I have a cnc gantry style router, that was retrofit with camsoft cnc professional software. When I run a series of plunged holes, to test repeatability, the holes oblong, and get a little deeper every cycle. When the servo motors are being held in position, I can overcome the holding power, with my hands, and with a dial indicator, I can move the axis back and forth. The axis does not return to the original spot. Is this a electrical noise issue, or is it a controlling software problem. I had the yaskawa tech bring a controller that hooks up to the amps, and they held solid, and always returned to their home position. I have a Galil motion card dmc-2152. The amps are in torque mode. What is telling the servo motors to hold position?