[bitfolk] Another slight apt-get oddity

Hi, The recent thread has reminded me of something.. I have two VPSes running Debian and each one checks for package updates once an hour, emailing me if there are any non-security ones available (security ones are installed automatically). Both use apt-catcher: first:# cat /etc/apt/sources.list deb http://apt-cacher.lon.bitfolk.com/debian/ftp.uk.debian.org/debian/ lenny main contrib non-free deb-src http://apt-cacher.lon.bitfolk.com/debian/ftp.uk.debian.org/debian/ lenny main contrib non-free deb http://apt-cacher.lon.bitfolk.com/debian/security.debian.org/ lenny/updates main contrib non-free deb http://apt-cacher.lon.bitfolk.com/debian/www.backports.org/debian lenny-backports main contrib non-free second:# cat /etc/apt/sources.list deb http://apt-cacher.lon.bitfolk.com/debian/ftp.uk.debian.org/debian/ lenny main contrib deb-src http://apt-cacher.lon.bitfolk.com/debian/ftp.uk.debian.org/debian/ lenny main contrib deb http://apt-cacher.lon.bitfolk.com/debian/security.debian.org/ lenny/updates main contrib deb http://apt-cacher.lon.bitfolk.com/debian/www.backports.org/debian lenny-backports main contrib non-free .. so first looks at the non-free bits of the main Debian archives and second doesn't, but apart from that, they're the same. The oddity is that the second VPS usually picks up updates more than an hour before the first one. One example was on 14th January this year, when there was an update to mysql-server-5.0 from 5.0.51a-24+lenny4 to 5.0.51a-24+lenny5. The second VPS noticed this at 9.37am, but the first one only started emailing me at 11.37am. Both continued happily emailing me once per hour until I did the update, so the script is indeed running once per hour on both.. .. so any ideas why the second one's seeing changes in the same set of files earlier than the first one? It's never been the other way around. Ian