On a Mac, Samsung Kies can get in the way of iSyncr working properly. Uninstalling Samsung Kies is the only work around for this issue. Even if you've never installed Kies on your Mac, the driver may still be on your Mac blocking iSyncr.
Uninstall Kies using terminal Always use terminal with caution. :
Open Terminal on your Mac. From the $:
rm -rf ssuddrv.kext
This will uninstall the Kies driver from your Mac.