Hi Barry,
One way to possibly confirm whether CM is off or on is to check the 100% patch in your target. In Photoshop use the eyedropper to find the location of the target patch that is calling for 100% yellow (255=R, 255=G, 0=Blue). Then, when you know where the patch is, look at this patch on your printed target: If there are any other inks in there besides yellow, that is confirmation that CM is happening.