installation using manual partitioning fails

Binary package hint: partman-target

- using CD-image from cdimage.ubuntu.com 3rd of september 2008
- cd-integrity check reported no errors
- started installer and used "manual partitioning" to preserve /home partition
- the single disk in the system under hardy was partitioned like this:

/dev/sda1 ext3 /boot 100 MBytes
/dev/sda2 swap 4 GBytes
/dev/sda3 ext3 /home 30 GBytes
/dev/sda5 ext3 /tmp 5 GBytes
/dev/sda6 ext3 / 4 GBytes
/dev/sda7 ext3 /var 4 GBytes
/dev/sda8 ext3 /opt 14 GBytes
/dev/sda9 ext3 /usr 15 GBytes

- the layout was kept, but every partition except /home (/dev/sda3) was set to be formatted
- installation went fine
- after first reboot grub failed ot boot the machine and reported:

GRUB Loading stage1.5.
GRUB loading, please wait...
Error 15

- also trying to use the live-cd to boot from the first hard-disk failed with the same error
- the contents of the /boot partition after the installation look like this:

abi-2.6.27-2-generic
config-2.6.27-2-genric
lost+found
memtest86+.bin
System.map-2.6.27-2-generic
vmcoreinfo-2.6.27-2-generic

- the /var -partition is empty except for the lost+found directory, thus no /var/log/installer/*
- the output of "sudo parted /dev/sda print all":

Model: ATA FUJITSU MHW2080B (scsi)
Disk /dev/sda: 80.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
 1 32.3kB 101MB 101MB primary ext3 boot
 2 101MB 4196MB 4095MB primary linux-swap
 3 4196MB 34.9GB 30.7GB primary ext3
 4 34.9GB 80.0GB 45.1GB extended
 5 34.9GB 40.0GB 5117MB logical ext3
 6 40.0GB 44.1GB 4095MB logical ext3
 7 44.1GB 48.2GB 4095MB logical ext3
 8 48.2GB 63.6GB 15.4GB logical ext3
 9 63.6GB 80.0GB 16.4GB logical ext3

- the contents of the /home partition were left untouched