Changing versions prevents slot edits being loaded

[grahamwhaley]

I noticed that slot saving was not taking effect after a reboot.
It turns out that if you have changed firmware versions, as we have a version dependant fingerprint in the eeprom settings, the firmware will 'default' due to an eeprom version mismatch, and load the default settings on boot - thus, skipping loading any setting changes that are stored in the eeprom.
So, the settings you edit do afaict get saved in the eeprom, they just won't get reloaded if there is an eeprom version mismatch.
The quick workaround/fix is to do a settings factory reset, which should rewrite the defaults of the current firmware into the eeprom (including the fingerprint), and then you should be able to save/load again.

If we were to make this 'really nice', we'd probably notice the eeprom version did not match the firmware, and in the settings menu 'persuade' the user they need to do a factory reset of the settings. We probably should not auot-reset the eeprom - take the 'path of least surprise' for the user.