how to sync Spinn with iMac?

[GB75]

I own an intel based iMac and would like some help from anyone on how to sync the Spinn with it. At present the supplied usb data cable has managed to charge the Spinn.

iMac doesnt pick it up at all not even as an external drive.

Im not keen to make the iMac dual bootable i.e. with XP, Win7 if anyone knows anyway I can get the two to sync would be greatly appreciated.

iRiver website is absolutely awful no decent support at all.