Video Settings Aren't Always Saved

For me the brightness option gets reset. Every now and then, when I start the game, the brightness is set to the default (moody) after setting it to +50% the former time I played.

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It looks like, for at least the video settings page, there's an options state in memory that saves and updates the game, as expected, whenever you press 'done' or the 'esc' key.
However, options.txt is only saved-to when you press 'done', and not when you press the 'esc' key.