I'm getting some apt-get error with mozilla repository, anyone else getting these?


apt-get update gives the following error in the end:

W: GPG error: http://moff.mozilla.com fremantle Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 667387BFFF445C24
W: You may want to run apt-get update to correct these problems


apt-get autoremove gives me this summary:

0 upgraded, 0 newly installed, 0 to remove and 17 not upgraded.


Why there are 17 not upgraded? Is it because of the error in the apt-get update process?

Thanks for your help to a linux noob! =)