I tried downloading the boot.img file again, and then I created it over again using the Windows version of rawrite, which I just happened to discover in the dosutils folder when trying to find a solution. When created with rawwritewin, the boot disk worked perfectly. It was definitely an installer bug, but it was one I created by trying to use an older version of rawrite from a Red Hat 6.2 CD-ROM. The dual boot was successful but I didn't use GRUB or LILO, I am just booting into Linux from a floppy for now.
> That must be an installer bug. Can you please send your system > information > including: > Processor > Motherboard make and model > RAM > peripherals > etc.