Package cannot be authenticated during system installation

[Baczek]

Ubuntu 10.10, alternate preseeded installation, /var/log/syslog

Jun 24 11:39:03 in-target: Reading package lists...
Jun 24 11:39:03 in-target:
Jun 24 11:39:03 in-target: Building dependency tree...
Jun 24 11:39:03 in-target:
Jun 24 11:39:03 in-target: The following extra packages will be installed:
Jun 24 11:39:03 in-target: linux-firmware linux-image-2.6.35-28-generic linux-image-generic
Jun 24 11:39:03 in-target: wireless-crda
Jun 24 11:39:03 in-target: Suggested packages:
Jun 24 11:39:03 in-target: fdutils linux-doc-2.6.35 linux-source-2.6.35 linux-tools
Jun 24 11:39:03 in-target: Recommended packages:
Jun 24 11:39:03 in-target: grub-pc grub lilo
Jun 24 11:39:03 in-target: The following NEW packages will be installed:
Jun 24 11:39:03 in-target: linux-firmware linux-generic linux-image-2.6.35-28-generic
Jun 24 11:39:03 in-target: linux-image-generic wireless-crda
Jun 24 11:39:03 in-target: 0 upgraded, 5 newly installed, 0 to remove and 42 not upgraded.
Jun 24 11:39:03 in-target: Need to get 46.8MB of archives.
Jun 24 11:39:03 in-target: After this operation, 134MB of additional disk space will be used.
Jun 24 11:39:03 in-target: WARNING: The following packages cannot be authenticated!
Jun 24 11:39:03 in-target: wireless-crda
Jun 24 11:39:03 in-target: E: There are problems and -y was used without --force-yes