Mike, I've just looked at your Mach forum thread.
the outside DIA. is supposed to be 12.5, the ID of the pockets is supposed to be 2"
the pockets keep coming out 2 1/16" and the OD is 12.375"
Where do you have Machine Vectors set to in the profile toolpath? Outside, inside or on? You're expecting a circle of 12.5" and you're getting 12.375". The difference between those is 1/8" which is your bit radius so that would lead me to think that you're cutting on the line rather than outside it which would be the norm.