Brian,
Thanks for the reply.
Yes, replacing the XPFM corrected the problem for the last 9 months, but now it's failed again.
Regarding the XPT, actually the original switch and module were Leviton installed by an electrician. When the lights stopped working the first time, I discovered water in the junction box outside. So I replaced the module with the X10 XPFM (my electrical supplier carries X10 and said the FM would work with the Leviton controller) and weatherproofed the box. The module failed about 1 month later so this time I replaced the controller AND the FM, both new X10 units. That's the combination that worked for the last 9 months.
Yes, it's only the off command that isn't responding.
The FM controls 2 fixtures, each has 2 40w candelabra base incandescent bulbs.
You mentioned that some type bulbs make noise when on and may interfere with an 'off' command. Do you know if candelabras fit that bill? Is there another type FM that would work better?
TIA,
Beck