I tried to install knoppix on a system that has two IDE disks in it and ran into several problems. The system was previously running FreeBSD so I know that it wasn't a hardware/BIOS problem.

I ran the install script and then tried to boot from hard disk, but the bios didn't find any OS or boot loader. I then reinstalled and found out that the lilo part of the install failed. I then installed lilo manually but when the machine tried to boot I got the message lilo timestamp mismatch

I then disabled the second disk and from that point on everything was a snap. Lilo was able to boot, I had to reinstall later, but this time when I ran usr/local/bin/knx-hdinstall it ran without any issues.