Cannot Update

[renlux]

I tried to update using the update manager and I got these messages:

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

W: Failed to fetch http://ph.archive.ubuntu.com/ubuntu/dists/intrepid-updates/Release

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

What do I need to do?

[lemming465]

In a terminal window try

sudo -i
apt-get clean
apt-get update
apt-get upgrade
Does that improve things any?

[SOULRiDER]

Check this out
http://ubuntuforums.org/showthread.php?t=1031404&highlight=40976EAF437D05B5&page=2