From what I've been hearing here and elsewhere (LSP forums), the LOR controller may be "self-terminating" on the last LOR controller when the TX is plugged in (or if you don't have the TX plugged in when you power the LOR controller).
Perhaps the TX doesn't put enough load on the LOR output to disable the self-termination, but when you plug in a LE controller it does. Do you have the termination jumper in place on the TX?
In another setup, he couldn't get the Renard controllers to work before/after an LOR controller, but could get it to work when he moved the Renards.
You could also try a DMX splitter before the LOR controllers and run the TX from that...I have an extra if you want to borrow one...