ELDK 3.1 installation tells me "Wrong format of the rpm archive"

[Edward Jubenville]

I tried installing ELDK 3.1 on RedHat 9,
but all I got was this:

   Installing cross RPMs
   Wrong format of the  rpm archive.

I'm a rookie, so I'm sure I screwed something up. I had downloaded
the ISO image to my Windows PC, made the CD there, copied the tree
onto my Linux box at /ELDKCD, then tried:

        ./install -d /ELDK
and
        ./install -d /ELDK ppc_6xx

What did I do wrong?