It doesn't really synchronize in the way that it seems you're wanting it to. When you start emplode, it has no knowledge of either your PC's filesystem or the empeg. When it connects to the empeg, it downloads its database. The files in the empeg are in no way related to the files on your PC, as far as emplode is concerned. If you want to change something on the empeg, you'll have to tell emplode to change it. That means that if a file's ID3 tag has changed, you'll have to delete it from the empeg and re-upload it (by dragging or whatever) via emplode.