This is an old post but seems to be similar to many others in the forum. It's a stab in the dark but I have a suggestion to try if this happens to you. In the TOOLS menu of AHP "Clear The Interface Memory" before downloading your program. I don't know if it's possible or how X-10 tests the CM-15A before shipping it but there might be test programs left over in memory that are reacting to your transreceive commands, or if you have any in your program, dangling (unfinished) macros doing the same thing. As I remember it there was a similar problem with the CM-11A. I always cleared memory on the CM-11A before downloading a new program and do the same thing now on the CM-15A and had/have no trouble with either. You could try "Purge Delayed Macro Events" if you're not downloading a new program, but, the very first time you set it up, clear the memory just to be sure.
