Can't import my tracks into playlist since v11

I have an album of .mp3 in a folder on my mac. In itunes, I used to have an empty playlist (normal, not smart) for importing. I would simply drag my song files into the empty white space when the playlist was selected, it would import, then the songs showed up, either individually or as an album.

Since v11, when I drag the files into the empty playlist, it imports them *somewhere*, but I can only see them in the system-created smart playlist "recently added". They do not show up in my empty playlist when I drag them there.

What could be happening?