To save the edited photos just click on the 'Save Button' button in the bottom right-hand corner of the PhotoInfoEditor window.
PhotoInfoEditor will NOT overwrite your original picture files, even if you try to save the edited pictures back to the folder containing the original photos.
If any photo files have been moved since the files were imported you will get a warning window in which you can:
Alternatively, the 'missing' photos can be ignored and the pictures that can be located can be saved and updated with the new meta-data.