Synaptic showing Key Error?

[etdsbastar]

Hello there,
I am getting this error while Reloading in synaptic, please help friends:

W: GPG error: http://archive.canonical.com precise Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://extras.ubuntu.com precise Release: The following signatures were invalid: BADSIG 16126D3A3E5C1192 Ubuntu Extras Archive Automatic Signing Key <ftpmaster@ubuntu.com>

W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG F1773AF13B1510FD Launchpad PPA for GNOME3 Team
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG 3EE66BD3F599ACE3 Launchpad PPA for pasgui
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG 464AD83D4631BBEA Launchpad equinoxart
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG B6C6326781C0BE11 Launchpad All you need for Ruby/Rails development on Ubuntu
W: GPG error: http://ppa.launchpad.net precise Release: The following signatures were invalid: BADSIG C2518248EEA14886 Launchpad VLC
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/precise/Release  

W: Some index files failed to download. They have been ignored, or old ones used instead.

[dino99]

have you tried to check these urls into a browser ?

http://askubuntu.com/questions/13667...-of-gpg-errors

[etdsbastar]

have you tried to check these urls into a browser ?

http://askubuntu.com/questions/13667...-of-gpg-errors

Not yet checked but trying the link you provided.