Hopefully I'll have some time later to look at the Fan controls.
As far as I know, no one really has a decent UPB, Insteon or X-10 fan control although I was asked to test one, but my I havn't got my power line control network together yet. X-10 is not the way to go. I'm replacing an X-10 system. Ceiling fans are tough to control. Dimming modules typically cause an annoying buzz.
I don't really know what you have. Any data would be helpful.
I have a couple of suggestions, but I'll have to do some research.
Suggestion A
Let's put a 15 or 20A RFI filter on that power line at the breaker box. What this would mean is, removing the wire for the circuit. Put a J-Box on the wall with the filter in it and then reconnect it.
Suggestion B
I'll see if I can find some ferrites that can be looped around the power wires that might fit where the controller is.
A&B can be used together. The filter really needs to be at the device, but some attenuation would occur if it was at the breaker panel.
Could you estimate the amount of wire (one way) from the panel to the fan control?