CimmerianX 197 Junior Poster

I'm running through a Ubuntu Auto install project. Using this as the starting point https://help.ubuntu.com/12.04/installation-guide/i386/automatic-install.html

I'm hitting a wall here regarding the root device. I'm thinking it has something to do with the partitioning.

Here is my very simple preseed file:

d-i debian-installer/locale string en_US
d-i console-setup/ask_detect boolean false
d-i console-setup/layoutcode string us
d-i netcfg/get_hostname string unassigned-hostname
d-i netcfg/get_domain string unassigned-domain

d-i netcfg/choose_interface select auto
d-i netcfg/wireless_wep string

d-i base-installer/kernel/override-image string linux-server
d-i clock-setup/utc-auto boolean true
d-i clock-setup/utc boolean true
d-i time/zone string US/Pacific
d-i clock-setup/ntp boolean true

d-i mirror/country string US
d-i mirror/http/proxy string
d-i pkgsel/install-language-support boolean false
tasksel tasksel/first multiselect standard, ubuntu-server

d-i partman-auto/method string regular
d-i partman-auto/purge_lvm_from_device boolean true
d-i partman-lvm/confirm boolean true
d-i partman-auto/choose_recipe select atomic
d-i partman/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i passwd/user-fullname string Ubuntu User
d-i passwd/username string ubuntu
d-i passwd/user-password password insecure
d-i passwd/user-password-again password insecure

d-i grub-installer/only_debian boolean true
d-i grub-installer/with_other_os boolean true
d-i finish-install/reboot_in_progress note

I boot and the process begins, but ends at this point:

VFS: Cannot open root device "(null)" or unknown-block(0,0)
Please append a correct "root=" boot option; here are the available partitions:
sda driver: sd
sr0 driver: sr

Am I missing something very obvious in this process? Any thoughts or direction?