The highlighted lines (with squeeze in it) are incorrect. If these instructions are followed, apt-get update will fail with a 404 Not Found error. That can be confirmed when looking in http://volatile.debian.org/debian-volatile/dists/.Archive
The official archive of debian-volatile is available on the main site volatile.debian.org, but a network of mirrors is active and available.
Please only use either lenny/volatile or squeeze/volatile with
deb http://volatile.debian.org/debian-volatile lenny/volatile main contrib non-free
or
deb http://volatile.debian.org/debian-volatile squeeze/volatile main contrib non-freeIf you want to use the sloppy archive, use the following APT sources:
deb http://volatile.debian.org/debian-volatile lenny/volatile-sloppy main contrib non-free
or
deb http://volatile.debian.org/debian-volatile squeeze/volatile-sloppy main contrib non-freeThe integration into the main archive is planned and hopefully available for Squeeze.