In "unshuffled" mode, the order is the order of the tracks or playlists that's shown in Emplode's "Position" column (in "details view.) So if you do a "down down down" to play all of your music and you're not shuffled, the first track in the first playlist will play. If you drill down deeper, the first track in the first sub-playlist (again, determined by emplode's "Position" field) is played. You can re-order these playlists and tracks by doing a "change sort order" in emplode, or by manually moving tracks up and down (holding Alt or Ctrl, I forget which, it's probably in the FAQ though.)
If you don't have the "Position" field listed in emplode, it can be added by right clicking on the column headers in "Details" view and choosing "Select Columns" or "Add/Remove Columns" or somesuch.