Import songs along with playlist?

It used to be that if I wanted to send a playlist of songs, in a specific order, to someone else, I could just export an .m3u file and place it in the same folder along with the song files. The recipient could simply open the folder, drag everything into iTunes or double click on the .m3u file, and iTunes would import the playlists and the associated songs along with it, in the correct order.

Ever since upgrading to iTunes 11, this no longer seems to be the case. I export a playlist as usual in .m3u, put it and the associated songs in the same folder and send away. When the recipient trys to import the playlist, the playlist and the songs all import, but the playlist is always empty.

I've tried various methods of importing - double clicking on the playlist file, dragging it and the songs into iTunes, dragging the whole folder into iTunes, importing the playlist via File -> Library, or Adding to Library. All the same result - an emplty playlist with the correct name shows up, and the songs show up in the library, but not attached to the playlist.

I've also tried all export formats (.m3u, .msu8, .xml, etc), and I've even tried changing library organization settings on both ends.

I'm sure it's something dumb on my part, but whatever it is, I haven't been able to find it.

All computers in the mix are running Mountain Lion. iTunes versions vary between 10 and 11, mostly 11 (I need it to work in 11).