We are running from a desktop latest thinghere, debounce looks like a good check. am looking at the switch inputs with scope and voltmeter. it looks like noise, the switch lines are on a pullup resistor to the limit/home switches, it is 10k from the power suppply/controller voltage. we had removed all the connections from the switches but left the wires running along the machine, they obviously can be picking up noise from the steppers, the big issue is when did the stopping start and what was the setup when it happened, the programmer made the changes while running the machine, I am the machine oversight but not the person running the machine. We also are trying to pin down if the controller is causing the problem as it is still under warranty. PS.. This project is to let this company see what cnc controlled pattern machining is all about. We are considering the next step with purchase of a Thermwood 5x5x12" machine, will lose the Mach2 at that time. cheers & thanks