Do not use the "Cut and Paste" or the "Move" features on songs and playlists in Emplode 2.0b7 (beta version). There is a bug where, in certain situations, the things you move (whether they be playlists or songs) could be completely deleted instead of just moved.
This will be corrected in the next beta. In the meantime, it is recommended that you use the official 1.03 version if you plan to do any music organizing on the player. It is fine to downgrade to 1.03 from 2.0b7, provided that you do it for both Emplode and the player software. Please see here
for details on how to upgrade or downgrade.