Possible Duplicate:
How do I fix the GPG error “NO_PUBKEY”?
Whenever I try to download package information from all configured sources using
sudo apt-get update
I get:
W: GPG error: http://ppa.launchpad.net oneiric Release: The following signatures could not be verified because the public key is not available: NO_PUBKEY 5A9A06AEF9CB8DB0
(/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_oneiric_partner_binary-amd64_Packages)
W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/ oneiric/partner i386 Packages (/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_oneiric_partner_binary-i386_Packages)
What could be the issue?