I've added those lines to my lilo.conf, but I still get the exact same error as the original poster.

I've tried several different installation options, under several different kernels.

The installation appears to be broken for a number of people.

Edit:

The following is the output of my installation attempt:

---

root@ttyp1[knoppix]# knoppix-installer-latest-web
This script will download and start the latest knoppix-installer to your home directory. Do you want to proceed? [Y/n]

--21:17:14-- http://debian.tu-bs.de/knoppix/installer/latest
=> `-'
Resolving debian.tu-bs.de... 134.169.172.5
Connecting to debian.tu-bs.de[134.169.172.5]:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 28 [text/plain]

100%[====================================>] 28 --.--K/s

21:17:15 (273.44 KB/s) - `-' saved [28/28]

Downloading knx-installer_0.3-14.tar.gz ...
--21:17:15-- http://debian.tu-bs.de/knoppix/insta..._0.3-14.tar.gz
=> `knx-installer_0.3-14.tar.gz'
Resolving debian.tu-bs.de... 134.169.172.5
Connecting to debian.tu-bs.de[134.169.172.5]:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 80,659 [application/x-tar]

100%[====================================>] 80,659 95.56K/s

21:17:16 (95.34 KB/s) - `knx-installer_0.3-14.tar.gz' saved [80659/80659]

Can't remove /usr/share/applications/./ethereal.desktop: Read-only file system,skipping file.
Can't remove /usr/share/applications/./ethereal-root.desktop: Read-only file system, skipping file.
Can't remove /usr/share/applications/./qtparted.desktop: Read-only file system,skipping file.
Can't remove /usr/share/applnk/./Settings/Peripherals/kxconfig.desktop: Read-only file system, skipping file.
/dev/mapper/control: open failed: No such device
Is device-mapper driver missing from kernel?
/dev/mapper/control: open failed: No such device
Is device-mapper driver missing from kernel?
Incompatible libdevmapper 1.00.19-ioctl (2004-07-03)(compat) and kernel driver
Warning: Unable to determine video adapter in use in the present system.
Fatal: open /usr/share/lilo/contrib/debian.bmp: No such file or directory