It's working now.
All of my Neo Geo games were in .rom format in .zip files. I downloaded some zipped in .bin format, and now they work.
The readme (read.mi) that the author wrote is lacking in it's explanation of how to get Gxgeo working. It does not mention that they roms should be in .bin format. As well, it doesn't mention that the config file in apps/conf needs to be altered (or even how to alter it!!!). I would hope that this is made clear in future releases of the read.mi file.
Other than that, very nice work... now that it's working!