How to force d-i to ask for domain name?

[Josef Wolf <jw@raven.inka.de>]

Hello folks,

I have preseeded netcfg like this:

  d-i netcfg/disable_dhcp    boolean true
  d-i netcfg/confirm_static  boolean true
  d-i netcfg/get_ipaddress   string 192.168.1.1
  d-i netcfg/get_netmask     string 255.255.255.0
  d-i netcfg/get_gateway     string 192.168.1.1
  d-i netcfg/get_nameservers string 192.168.1.1
  d-i netcfg/get_hostname    string external-gw
  d-i netcfg/get_domainname  seen false

The intention is, that d-i asks me for the domainname.  AFAIR, This worked
as expected back in sarge days.  But now it don't ask anymore.  Any ideas
what I have messed up here?