The bootnet.img boot disk hangs after loading the second-stage ramdisk from a Microsoft Internet Information Server FTP server on NT Server 4.0 / SP4.
Are you sure it is IIS? I.e. have you tried retrieving the files via another ftp server, and been successful?
Does IIS support passive transfers?
Yes, I'm positive it's IIS, and I'm not sure if it supports passive transfers or not. It works fine installing off of ftp.redhat.com; I actually think it has something to do with the way I pulled the files off of ftp.redhat.com. I got a copy of the 5.9 blue CD, so I'll try copying that to the ftp server vs. copying it from ftp.redhat.com.