My MH871 was experiencing erratic cuts and on occasion would have a mind of it's own. I followed the directions to ground the cutter to the stand, but this did not work. I decided to open the cutter (not under warranty) to see if there was a loose connection. MAKE SURE THE POWER CORD AND CONNECTION TO THE COMPUTER ARE BOTH UNPLUGGED (I know it sounds silly to mention this). I removed the left end cap where the power cord plugs in. From the back of the outlet, you can see that there is a black ground wire screwed to the chassis of the cutter. Remove the screw for the ground wire and scrape the paint off around the hole. Replace the screw and ground wire, then the end cap. The ground wire for the power was not actually being grounded because there was no metal to metal contact. This fixed the problem that I was having and might save someone the trouble of thinking that it is there software or driver.
