Comment 24 for bug 305264

This bug may not be completely fixed, though I'm not sure -- check this out:

gnutls-cli -V --x509cafile /etc/ssl/certs/ca-certificates.crt login.launchpad.net

that tells me that the "Peer's certificate is NOT trusted", but with the "staging.landscape.canonical.com" in the original description it's working now (up-to-date intrepid).