So far I have 4 keypadlincs, some lamplincs, appliancelincs, accesspoints, rflincs etc and the X-10 still works fine. The Insteon communications is not the greatest but thats because I dont have enough in (and I may pull them out again unless I dare try switchlincs again LOL).
That's funny, because my Insteon has worked fine from the beginning, even though the X-10 has started to fade. I started by plugging in a single Insteon dimmer module at the point farthest from the panel, with the controller some distance from the panel on the opposite phase, and that lamp module worked just fine without any SignaLincs or any other Insteon devices to repeat the signal. [Yeah, I have a pretty small house. :lol: ] Even with both a PLC and a PLM plugged into the same outlet. I do have a passive X-10 couple (dryer plug-in type), but don't know whether that helps the Insteon signal in any way or not.
After five Insteon devices, the X-10 was still working fine. Then I installed three more Icon in-wall dimmer switches, and the X-10 stopped working to certain areas. I pulled the air-gap on the three new switches, and X-10 was back to normal. Pushing any one of the three air-gaps back in again caused the X-10 to fail, so yes it was a single Insteon switch which pushed the X-10 over the edge.