Thanks for the explanation. That's really what I was looking for, and yes, it turns out that the mini-plug needed to go in an extra "click," even though it looked like it was in all the way.

I make my own adapters, and this setup did require both a null-modem and male-male connection. Is there NO standard in this stuff??? My Denon processor is the only device that I have where I was simply able to plug in the Nevo serial module as is. Everything else requires an adapter of one sort or another. Do the other remote systems tend to put female DB9 connectors on their cables? These male-to-male connections are a PITA, as I end up with a 5-6" connector hanging off the back of most devices. :(