Spindle Turning off Intermittently-Mach3

Description of the problem:

The spindle is turning on/off intermittently 
If the oiler output (in the MachMotion plugin) is set to output1 or output2 (this is typical, but could be different depending on configuration of spindle tab settings in  ports&pins) is will cause the spingle to turn on/off inexplicably. Any other output should work.