Hi MDew - All the systems you use are good quality commercial systems and should work well. My first impression is to check the machine mechanics. Second is to send a sample code to strutcam and let them comment. Does the glitch show up in a toolpath simulation?

Ironcad - solid commercial CAD. I assume you use a step file to transfer to sprutcam. This should be a high quality transfer of geometry. I have had issues with the export displacing objects but this is immediately apparent.
Sprutcam - I've spoken to the local agent today about the robot OLP. The 3 axis mill program is high quality so should behave properly. I suspect its a machine looseness. But check with Sprut about the glitch
Pathpilot - again solid commercial MC so unless set up totally wrong should be fine
Tormach router - solid commercial machine - check mechanicals

thanks for contributing - Peter