You should not save scenes as preferred scenes in General Preferences, especially if they do not have specific, identifying names. I do not believe you will be able to recover your original setup because it has been overwritten. To properly save the scene in Poser, use the Save or Save As commands. Name each save appropriately, and if you are making multiple sets of different scenes, label them as VER01, VER02, etc. This method enables you to load previous files.