I'm going to call this afternoon if I get a free moment. I just thought that maybe I had found a cleaner/easier fix...
After doing some more reading it also looks like there is a Ferrite Bead that can be installed in the head of the Terrova for RFI. I may ask about that as well.
If I can prevent the RFI from the PWM from traveling down the power wires in the first place, that may keep it from jumping onto the ethernet cable. I realize that is all theory:). RFI is a crazy thing!