I got his error today for the first time:
I ran apt-get in Gutsy and...
W: GPG error: http://security.ubuntu.com gutsy-security Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email address hidden>
As discussed above the following command fixed this for me:
$ sudo apt-get update -o Acquire::http::No-Cache=true
I got his error today for the first time:
I ran apt-get in Gutsy and...
W: GPG error: http:// security. ubuntu. com gutsy-security Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email address hidden>
As discussed above the following command fixed this for me:
$ sudo apt-get update -o Acquire: :http:: No-Cache= true