@jennyc: Make sure you delete any other versions of NewSoftSerial from your /libraries/ folder (I assume that is what you meant - if not, you need to use that folder instead). Then use this version of NewSoftSerial:
http://code.google.com/p/rogue-code/downloads/detail?name=NewSoftSerial10c-withMegaAndStream.zip
The start-up sounds right. Activity LED should flash briefly, then turn off. Just make sure that the controller board (Uno) is not connected to the computer when you attach the rMP3. After attaching, plug the rig into your computer.
b