The funny thing is, you never really disable
RF reception on the CM15a, you just disable
RF to AC line transmission. Consequently,
you get this:
/TM751 -> Powerline
RF signal-> and
\CM15a -> Run Macro -> Powerline
The result: 2 powerline transmitters are
sending at the same time.
To really oversimplify things, x10 codes are
a timed series of 0s and 1s. If one
transmitter is sending 1001 and another
overlaps with 0110, it comes down the
powerline as 1111. If the corrupt signal
works out as a valid code, you might well
trigger another device or cause the CM15a to
run an entirely different macro...
The CM11a escapes the problem because it
isn't as fast to respond as the new unit is.
That's why I suggested the delay at the
start of your macro, to "emulate" the delay
on the CM11a.
In any case, I can understand you just
wanting to go back to the CM11a. Mine was a
workhorse. Too bad it can't be upgraded to
support conditional macros (without
dedicating an always-on computer, or building
a dedicated "controller-controller", that is)!
Tom