Please describe the problem:
Since 0.12.x, I have trouble dragging a song onto a playlist.  When I drag the song over to the playlist manager, the playlist manager scrolls to some arbitrary point near the top of the list of playlists, so I can never get my song onto a playlist in the bottom.

Steps to reproduce:
1. Have a list of playlists that is longer than will fit on the screen.
2. Select your library, so that the browser is showing your library.
3. Scroll the list of playlists to the bottom.
4. Try to drag a song from your library to the playlist.

Actual results:
The list of playlists is scrolled to the top.  You cannot drop your song on the correct playlist.

Expected results:
The list of playlists would stay scrolled to the place it was before, and you could drop the song on the playlist on the bottom.

Does this happen every time?
Yes.

Other information:
New in 0.12.x.