Resolving apt-get unmet dependencies

[axelle_apvrille@yahoo.fr]

Hi,
I'm sure this is pretty simple, but I can't get it to work...

Can somebody explain how I can install libc6-dev ?
I keep getting an error message from apt-get, which I do not know how to
solve:
#apt-get install libc6-dev
...
The following packages have unmet dependencies:
  libc6-dev: Depends: libc6 (= 2.3.6.ds1-13etch2) but 2.6.1-3 is to be
installed
E: Broken packages

My sources.list is:

deb cdrom:[Debian GNU/Linux 4.0 r1 _Etch_ - Official amd64 NETINST
Binary-1 20070820-20:16]/
etch contrib main

deb http://ftp.fr.debian.org/debian/ etch main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ etch main contrib non-free

deb http://security.debian.org/ etch/updates main contrib
deb-src http://security.debian.org/ etch/updates main contrib

Regards,
Axelle.