Seems somewhat unpredictable to me.
That's probably because of how the refresh works. You de-select the seen flag and the previously recorded date seen (in the separate field, not the one beside the flag) doesn't disappear. You refresh, and it still doesn't disappear. But when you refresh, note the item in the list is no longer selected—so the movie pane is not actually refreshed. Select the item in the list again to see the refreshed version—the date will be gone.
The refresh function needs to be improved. I don't think it's much of an issue here, but it's behaviour is very annoying in other situations. If one item in a long list has been selected and then a refresh occurs, it loses focus in the list. Although the same movie appears in the movie pane, it's no longer selected. That means no operation can be performed on it until it is re-selected. But the list has been refreshed, so that requires a lot of scrolling or a search to locate the movie again.
