The last two days I’ve been getting the following breakage email from the daily updates script on one of my etch Xen domains:

/etc/cron.daily/local-apt:
W: GPG error: http://admin.curacao.strugglers.net etch
Release: The following signatures couldn't be verified
because the public key is not available: NO_PUBKEY
010908312D230C5F
W: You may want to run apt-get update to correct these problems

On further investigaton it seems to be because etch’s APT is now checking signatures against a GPG key I do not have configured. Thanks to JackieBrown’s post at DebCentral (and Google), a solution is found. Read more on the wiki.