Hi Martin.
I’m not sure, but I think this is the way it’s supposed to work. You have to choose “High-Quality Mode” to be able to save a MP3 preset with 48.000 kHz. I could be wrong though?
Yes, I have to agree. There’s no logic in this settings window. But until it gets fixed (if it ever gets fixed…) this is yet another “workaround”… By choosing High-Quality Mode You can save the MP3 preset with 48.000 kHz and the settings will recall correctly next time You open Your preset.