Comment 14 for bug 52814

The problem here is that there is no Default for the pnm2ppa/printer_model template. debconf's Noninteractive frontend handles a select question with no default by picking the first one; cdebconf doesn't do this (which I think is arguably a cdebconf bug, so I've opened a cdebconf task on this bug). The practical effect of this is that installs from the desktop CD will generate a correct pnm2ppa.conf, since debconf is used to build the live filesystem, while installs from the alternate install CD will not, since debconf passes everything through to cdebconf there.

You can and should work around this problem in pnm2ppa by supplying a Default, like this:

 Template: pnm2ppa/printer_model
 Type: select
 Choices: 710, 712, 720, 722, 820, 1000
+Default: 710
 _Description: What model of HP Deskjet printer do you use?
  The pnm2ppa printer filter behaves differently depending upon which HP
  DeskJet model you use. Choose your model of printer for the default
  configuration file /etc/pnm2ppa.conf.