Ubuntu 12.04 preseed LVM partitioning

Автотусклый гm attempting to the installation of Ubuntu 12.04.5 LTS using в preseed file, but гm still getting prompted to confirm в Yes/No at в disk partitioning window. The question being asked is "Write the changes to disks and конфигурировал LVM?". This is the partitioning section of my preseed file:

d-i partman-auto/disk string /dev/sda
d-i partman-auto/method string lvm
d-i partman-lvm/device_remove_lvm boolean true
d-i partman-md/device_remove_md boolean true
d-i partman-lvm/confirm boolean true
d-i partman-auto-lvm/guided_size string max
d-i partman-auto/expert_recipe string                         \
      boot-root ::                                            \
              40 50 100 ext4                                  \
                      $primary{ } $bootable{ }                \
                      method{ format } format{ }              \
                      use_filesystem{ } filesystem{ ext3 }    \
                      mountpoint{ /boot }                     \
              .                                               \
              500 10000 1000000000 ext4                       \
                      $lvmok{ }                               \
                      method{ format } format{ }              \
                      use_filesystem{ } filesystem{ ext3 }    \
                      mountpoint{ / }                         \
              .                                               \
              64 512 300% linux-swap                          \
                      $lvmok{ }                               \
                      method{ swap } format{ }                \
              .
d-i partman/confirm_write_new_label boolean true
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select Finish partitioning and write changes to disk
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true

What am I missing?