I was referring to non-Smarthome X10 devices containing BoosterLinc technology. From the KeypadLinc User Guide (all the User Guides contain this warning) ….
“If you have installed older Smarthome Plug-In BoosterLinc™ X10 Signal Boosters or certain other BoosterLinc-enabled products, the older BoosterLinc technology may interfere with INSTEON communications.”
All the newer Smarthome actual BoosterLinc devices do not interfere with Insteon. It comes up from time to time on the Smarthome forum when a user is moving from an X10 installation to an Insteon installation. Seems rather common for some of the X10 devices (not necessarily from Smarthome) with BoosterLinc circuitry interfering with Insteon.