I just played 5 or 6 tracks in a row. I wasn't watching most of the time, but I watched the last two tracks. Last Played gets updated as soon as the track starts. So does [Number Plays]. Unfortunately, [Number Plays] gets incremented *again* at the end of the track. So a track that is played once, adds 2 to [Number Plays]; one at the beginning, one at the end.
When playing to a local device, [Last Played] and [Number Plays] only get updated at the end of the track.
So there's definitely something weird going on, at least in my test scenario.
Brian.