Mystery-solved! 
After 5 evenings of research, I figured out why my new URC MX-980 remote was seemingly plagued by the fact that it failed to control my Lightolier Compose PLC lighting control system: The lighting bolt that struck very near our house in early July while we were up north at a lake for a week apparently did a bit more than just scramble the brains of my lighting controller. Some of you may recall my recent thread which discussed the incident and the eventual determination that the lightening didn't fry anything; it simply set the controller's logic address to a different one that no longer matched any of the 11 zones it controls. Setting it back to the default address cured that issue. However, I now discovered that the lightening also changed the Infrared (IR) remote sensor's status to the "OFF" position. This was discovered when I realized the controller would not respond even to the Model: CLMIRTES remote that came with it! There are 5 possible settings: "Rooms 1, 2, 3, 4 and OFF". I reset the controller to respond to Room 1 commands and viola: The lights now respond via the MX-980 remote from anywhere in the house via the RF to IR extender.
The final thing I have to do is to connect the projector IR emitter to the RF extender and the entire theater will be remote-wise, back-in-business once again! I am nearly finished messing around with the remote's programming and I must say that the URC Complete Control Editor software has made this a relatively easy task. There is a bit of a learning curve for folks who have never programmed a sophisticated remote before. But, having owned and programmed a Phillips Pronto NG remote for the past 4 years, pretty much made programming the MX-980 a walk-in-the-park. So far, so good! - Glenn
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