What happens when you hit your 'folders' or 'search' quick launch buttons?
Try going to view> choose details, too.
I've been trying to duplicate what you have. Can't figure it out
Does explorer open in one big window no matter where you open it to, or is it just your mp3 folder? If it's just the mp3 folder, open it somewhere else and go to tools> folder options, and apply the view from a 'good' view to all folders... maybe that will fix it.