Sorry folks, false alarm. I have now succeeded in persuading apt-cacher to serve up udebs quite happily to the d-i:
my.server:3142 as the server (no separators) and /debian.virginmedia.com/ as the path (note separators at both ends - Virgin's Debian mirror does not use the traditional /debian/ directory, hence it is not included). This works fine - I'm not sure what was wrong before, maybe I just had a problem connecting to ftp.uk.debian.org CC This e-mail may contain information which is confidential, legally privileged and/or copyright protected. This e-mail is intended for the addressee only. If you receive this in error, please contact the sender and delete the material from your computer
