create hdd image with LXDE desktop without libreoffice

["upiter77@lycos.com" <upiter77@lycos.com>]

Hi

Howto create live hdd with LXDE desktop without libreoffice?

I've created config/chroot_apt/preferences file:

Package: libreoffice
Pin: version *
Pin-Priority: -1

but I get this problem during image creation:

The following packages have unmet dependencies:
 task-lxde-desktop : Depends: lxde but it is not going to be installed
                     Recommends: libreoffice-gtk but it is not going to be installed
                     Recommends: libreoffice but it is not installable
                     Recommends: libreoffice-gcj but it is not installable
                     Recommends: libreoffice-help-en-us but it is not going to be installed
                     Recommends: mythes-en-us but it is not going to be installed
                     Recommends: system-config-printer but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
P: Begin unmounting filesystems...
P: Saving caches...
Reading package lists... Done
Building dependency tree       
Reading state information... Done

greetings
Piotr