Go to Settings/System Settings/Info. Does that show the internal memory with a lot of empty space?
Since you formatted the unit, it wiped out any files you added to internal memory, so it makes sense that it’s not showing anything you had there. It should only refresh if you’ve added or changed something–but it’s possible the Mac does some kind of funny business that makes it refresh each time.
Having formatted, you’ve ruled out a bad file in the internal memory. Which leaves two possibilities: a bad cord or a firmware glitch.
Connect it to a PC. If the cord is good it will show up as two drives: SANSA CLIP (internal memory) and Removable Disc (the card slot). If it does, download the firmware from the sticky thread near the top of the forum, unzip it and drag the unzipped folder (or it might just be a .bin file, I forget) onto the SANSA CLIP driveletter. When you disconnect it will update the firmware.
