Hmm... How to publish a picture? :)
In detail, IR outputs of RFX contain 2 pairs of jacks. When both jacks in pair are with 2-head flashers, it looks like:

+9V -> jack tip -> LED -> LED -> jack sleeve -> jack tip -> LED -> LED -> jack sleeve -> signal (+4V...+9V)

When only one 2-head flasher in jack and other jack is empty, it mechanically commutated as

+9V -> jack tip -> LED -> LED -> jack sleeve -> R=120 Ohm -> signal (+4V...+9V)
or
+9V -> R=120 Ohm -> jack tip -> LED -> LED -> jack sleeve -> signal (+4V...+9V)

So, when anybody tries to connect jack sleeve to ground, it "scares" enough both of RFX and Niles or Xantech IR distribution systems :)

If you want to escape the RFX disemboweling, the only one safe way is to use a real IR transmitting: from Philips IR flasher into Xantech IR receiver like, say, 291-00 :)