When playing a song, it looks like Famitracker is highlighting and scrolling to the row it's about to play, then after it plays the note, immediately moves to the next row. It's a little unexpected, because you see a row highlighted with notes that aren't actually playing. Normally I'd expect the program to move to the row as it begins to play the notes, rather than moving to the row so early.
Is this related to me using a 60ms sound buffer? If it is, maybe try to lag the visuals so the audio and video stays in sync.
I noticed the same thing long ago but I always assumed that's how it should be - if the cursor is on row 00 and you hit play, it plays row 00, moves to 01 and waits until the timer tells it to play it, then it moves to the next row, etc. Makes sense to me... But I dunno.
Yeah this is how it's designed, the cursor moves down once a row is played. There is no particular reason though, this was how it turned out when I first made it.