packages aren't being verified in apt-get under testing
I upgraded to etch a while ago, and when the secure version of apt was 
uploaded I had to add the secure-testing security archive key, but 
otherwise it's worked fine.
Recently however when doing dist-upgrades, apt-get has been warning that 
most packages cannot be verified.  I can still install them fine by 
selecting to continue, but obviously I want them to be verified.
I downloaded the latest key from http://www.debian.org/releases/ and 
added it using apt-key.  apt-key list now gives this output:
/etc/apt/trusted.gpg
--------------------
pub   1024R/1DB114E0 2004-01-15 [expired: 2005-01-27]
uid                  Debian Archive Automatic Signing Key (2004) 
<ftpmaster@debian.org>
pub   1024D/4F368D5D 2005-01-31 [expires: 2006-01-31]
uid                  Debian Archive Automatic Signing Key (2005) 
<ftpmaster@debian.org>
pub   1024D/8722E71E 2005-08-24 [expires: 2008-01-31]
uid                  secure-testing Archive Key 2005-7 
<katie@secure-testing.debian.net>
sub   2048g/A04E64FA 2005-08-24 [expires: 2008-01-31]
pub   1024D/2D230C5F 2006-01-03 [expires: 2007-02-07]
uid                  Debian Archive Automatic Signing Key (2006) 
<ftpmaster@debian.org>
but the problem still occurs.  I tried running apt-key update but that 
gives the error:
ERROR: Can't find the archive-keyring
Is the debian-keyring package installed?
The debian-keyring package is installed, however this only seems to 
provide debian-archive.gpg.  I tried running 'apt-key add 
/usr/share/apt/debian-archive.gpg' but the problem still occurs.
What's going on?  If I need a new key, which one & where do I get it?
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