Error when installing from IDE disk: "harddisk 0 uses a format not supported by ReactOS"

This was executed on a Debian machine to prepare an install disk:

$ dd if=ReactOS-0.4.13-release-14-g2494cfc.iso of=/dev/sdb

(/dev/sdb is a PATA HDD in a USB enclosure)

The target PC cannot boot USB disks (due to old BIOS), so the drive was installed as an IDE master on the primary IDE bus.  The target HDD was installed as an IDE slave on the same bus.  The ReactOS install disk booted and launched fine.  The installer correctly showed:

Harddisk 0: CDFS/ISO-9660

Harddisk 1: unpartitioned space

I then created a new partition on Harddisk 1 & selected that as the target.  The next screen shows that the installer detects itself on "C: CDFS/ISO-9660" and it says "harddisk 0 uses a format not supported by ReactOS". Yet I told it to install on "D:".  The installer could not make progress past that point.