I had recently bought the charger between phone and computer so that I can transfer ring tones from my computer to my samsung blast phone. However when I first tried to connect it, it said that I needed some kind of software so I downloaded the software that was recommended. I set my usb settings to mass storage but every time i try to put a ring tone in, it said that I need to insert a disk. Also it seems like the usb settings have modem mode and mass storage mode, what is the difference?