Trying to update some repositories on Debian Etch installation and getting the following errors from running "apt-get update"
W: GPG error: http://www.debian-multimedia.org etch Release: The following signatures couldn't be verified because teh public key is not available: NO_PUBKEY 07DC563D1F41B907
W: You may want to run apt-get update to correct these problems
The irony of it instructing me to run apt-get update is a nice kicker...
I found several posts telling me to run several gpg commands, but they didn't solve the problem because of two things. First, I was missing the debian-keyring package on my system and second I was using an invalid keyserver. Try different keyservers if you're getting timeouts!
Thus, the way I fixed it was:
apt-get install debian-keyring
gpg --keyserver pgp.mit.edu --recv-keys 1F41B907
gpg --armor --export 1F41B907 | apt-key add -
Then running a new "apt-get update" worked flawlessly!