Hi JohnnyH,

I did modify my souces.list. Then I did apt-get update. Here's the results:

Hit http://security.debian.org testing/updates/main Packages
Hit http://security.debian.org testing/updates/contrib Packages
Hit http://security.debian.org testing/updates/non-free Packages
Get:27 http://ftp.uk.debian.org etch/non-free Packages [83.6kB]
Get:28 http://ftp.uk.debian.org etch/contrib Packages [60.0kB]
Fetched 4780kB in 43s (110kB/s)
Failed to fetch http://ftp.uni-kl.de/debian-local/di...86/Packages.gz 404 Not Found [IP: 10.52.1.100 80]
W: There is no public key available for the following key IDs:
B5D0C804ADB11277
W: GPG error: http://sidux.com sid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 3916C431F80994F6
W: There is no public key available for the following key IDs:
B5D0C804ADB11277
W: GPG error: http://www.debian-multimedia.org etch Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 07DC563D1F41B907
E: dpkg was interrupted, you must manually run 'dpkg --configure -a' to correct the problem.
root@Knoppix:/etc/apt#

What next ?

Thanks,

Marc.