backtrack repos fails

W: GPG error: http://all.repository.backtrack-linux.org revolution Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AB6DA34B475A6B7F
work ~ # gpg --keyserver wwwkeys.eu.pgp.net --recv-keys AB6DA34B475A6B7F
gpg: requesting key 475A6B7F from hkp server wwwkeys.eu.pgp.net
?: wwwkeys.eu.pgp.net: Host not found
gpgkeys: HTTP fetch error 7: couldn't connect: No such file or directory
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0
work ~ # gpg --keyserver http://pgp.mit.edu/ --recv-keys AB6DA34B475A6B7F
gpg: requesting key 475A6B7F from http server pgp.mit.edu
gpgkeys: no key data found for http://pgp.mit.edu/
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0
work ~ #