Sounds like you're talking about the file selection bar? Like the row changes color to indicate which file you have selected?
If so, why would you want that to change automatically?
Consider this scenario... you're playing some music. While it's playing, you're also tagging files. You select a file and start tagging. MC then finishes playing the song it was playing and the selection moves to the next file in the playlist. Now the changes you're making in the Tag AW are happening to the playing song and not the one you specifically picked. Doesn't sound like a good idea to me.
Instead, you should see a little playback arrow on the currently playing file, which does follow along as the song changes.
