I did a little more playing around and have verified that the USB ethernet adapter is not the problem. I can ping the central okay. In fact, I was able to hit it with my web browser and download files or stream music from it.

However, the Emplode softare just won't find it, even on the same computer that I used to reach it with a web browser. I suspect it's a problem with the computer. I'll have to dig a little deeper there.