Exporting files for CAM

I use Rhinoceros 5.0 for modelling and I work with a 3D print company which uses PowerMILL cam software. I export a surface with one peace with STEP,STP formats, however while they import file to PowerMILL the surface explodes and turns three surfaces. How can I fix this problem? I try to ascii and step formats,

Thanks for your interests,

Ozan

Hi Ozan- can you post the object, or send it to tech@mcneel.com, with the same comments as above?

thanks,

-Pascal