Solve the NO_PUBKEY 07DC563D1F41B907

if with Debian testing we add the repository http://www.debian-multimedia.org it could happen that at the first apt-get update you get a GPG error:

W: GPG error: http://www.debian-multimedia.org squeeze Release:
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 07DC563D1F41B907

To solve this problem just install the debian-keyring package

# apt-get install debian-keyring

and then run this command:

# gpg --keyring /usr/share/keyrings/debian-keyring.gpg -a --export 07DC563D1F41B907 |apt-key add -

next time you update apt-get you will no longer get the GPG error.