Im having problems with Turbocadcam Pro v14, when i try to fillet a corner

When i draw a simple square pocket and generate the g codes they go through fine to my Prototrack MX2 but when i put just one 6mm radius on a corner the MX2 reads error 27 it is not possible to define an arc with the x,y and z given, when looking at the g codes there is a 0 value for I. I have spoken to the people at XYZ machine tools and they think that there must be a setting that is making the program think that the MX2 will know what the I value is. Can ayone help please. Grant