My symptoms are the same as Spock, but we have the OI-Mate-MB control. I thought electrical noise might be the problem too, but we just moved the shop and had the place professionally rewired. Whatever the fix is, it will be worth the money. I hate walking across the shop to fix this machine. Other than this little bug, it has been a great workhorse. Spock, I hope you will let us know what the repair man says. BTW, who is he and where is he located?