# Home repository
# ----------------------------------------------------------------------------------------------------
d-i apt-setup/local0/repository string
http://daisy/debian wheezy main
d-i apt-setup/local0/comment string Home repository
# Debian Mozilla repository
# ----------------------------------------------------------------------------------------------------
d-i apt-setup/local1/repository string
http://mozilla.debian.net/ wheezy-backports iceweasel-release
d-i apt-setup/local1/comment string Debian Mozilla repository
d-i apt-setup/local1/key string
http://mozilla.debian.net/archive.asc
# Debian Backports repository
# ----------------------------------------------------------------------------------------------------
#d-i apt-setup/local2/repository string
http://caroline/debian wheezy-backports main contrib non-free
#d-i apt-setup/local2/comment string Debian Backports repository
but in case this seem to be invalid bug report, feel free to close it.
(have to admit that my timing for finding bugs sucks since the I would like to see Jessie released soon :)