Thanks for this pointer...
After reading this, I tried installing, first with "pci=nomsi,nommconf" and then with "libata.dma=0". Both of these had the same result. Still can't see the IDE drive. Just the four SATA drives.
I have successfully installed and updated Fedora Core 6 on this machine so I know it works OK. Would it be easier to upgrade this system to F8 using yum? I can't upgrade it from the DVD for the same reason I can't install in the first place. Since the DVD system doesn't see the IDE drive, it doesn't see the existing system and so doesn't offer upgrade as an option.
Any other suggestions would be appreciated.