Let's try one more thing.  It is possible that the RNG 110 responds to 2 different IR protocols.  The two setup codes are 01376 (GI Cable, used in Motorola equipment) and 01982 (XMP, used in newer cable boxes).  I would first blink back the setup code that the remote is currently using for cable, and then try the other one.  You'll probably need to use the 982 command so that the remote will let you change the cable setup code.