"All Playlists" in Media Center -- "Media Center Viewed/Unviewed" field

I’ve got a user asking why some of their “Media Center Viewed/Unviewed” entries automatically reset to “Unviewed” after previously having been confirmed set to “Viewed”. Unfortunately this is second-hand info, but I’ve been asked to look into it. Is this something that’s possible?

Other than the obvious, playing a playlist item, and manually re-setting the values to “Unviewed” is there a means by which that field can re-set itself to “Unviewed”?

Also curious: Where is the “Viewed/Unviewed” information stored in the scheme of things? From what I can tell it’s unique to the user. In other words, just because one user plays a view list, causing it to change to “Viewed” or manually sets it to “Unviewed”, it doesn’t affect those entries for a different user viewing the same playlist, correct? So presumably that information is stored not in the “Playlist” table directly but a separate, linked table.

Is there a way to monitor the “Media Center Viewed/Unviewed” entries via API for ALL users?