The alternate gpt tends to be at the end of the disk - I suspect that the EFI partition table check attempts to read from the last block declared by the ipod, the scsi layer chokes (due to that block not actually existing) and then everything falls over. The real issue is why the USB quirk is executed when the hardware is plugged in directly, but not when via a hub.
** Summary changed: - EFI-support in kernel causes I/O errors with iPods + Ipods react badly to checks for EFI partition tables -- Ipods react badly to checks for EFI partition tables https://launchpad.net/bugs/37163 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
