When you go to save your own presets, note where it's saving the XMP file. (It should be in that same folder as the other presets you're trying to see.)
Not sure what's going on with the other presets. If you go to load just one XMP file, does it show up in the list?
I have noted where the XMP files save to and it is the same as the others, so I don't believe I'm saving n the incorrect place.
Still doesn't show up when loading 1 x XMP...
Did the folder also contain other presets? Did you try completely emptying the folder and then just try an XMP file or two?