Problems with my stepper motor

[tmd019]

I am having problems with one of my motors. I toggle the motor in a positive direction at different intervals. The motor will turn the correct direction during the first few intervals and then the motor will start going the other direction for an interval. I am using Mach3 and in the process of learning this program and setting up the CNC machine. My other two motors are running fine. Is there a problem with the motor or a Mach3 setting??

[ringram2077]

Could you swap two of your motors and see if the problem stays with the suspect motor ?