[edgy] installer crashed while grub-install

Binary package hint: ubiquity

1st, i startet nUbuntu Live-CD (nubuntu 6.10), then typed startx to get onto fluxbox.
next i set root-pw and switched to su
then apt-get update, apt-get install ubiquity, ubiquity in root-terminal

I set partition table manually:
   hda1 (21 GB) formatted as /
   hda2 (56 GB) no changes (existing Debian on this partition)
   hda5 (1 GB) swap space

then set language settings to german (keyboard layout etc.) and began installation.

The installer crashed at ca. 90% while installing grub.

logs can be found here:
http://parahill.de/syslog.txt
http://parahill.de/partman.txt

Traceback (most recent call last):
  File "/usr/bin/ubiquity", line 166, in ?
    main()
  File "/usr/bin/ubiquity", line 163, in main
    install()
  File "/usr/bin/ubiquity", line 57, in install
    ret = wizard.run()
  File "/usr/lib/ubiquity/ubiquity/frontend/gtkui.py", line 305, in run
    self.process_step()
  File "/usr/lib/ubiquity/ubiquity/frontend/gtkui.py", line 856, in process_step
    self.progress_loop()
  File "/usr/lib/ubiquity/ubiquity/frontend/gtkui.py", line 628, in progress_loop
    raise RuntimeError, ("Install failed with exit code %s\n%s" %
RuntimeError: Install failed with exit code 1
Traceback (most recent call last):
  File "/usr/share/ubiquity/install.py", line 1404, in ?
    install.run()
  File "/usr/share/ubiquity/install.py", line 385, in run
    self.configure_bootloader()
  File "/usr/share/ubiquity/install.py", line 1163, in configure_bootloader
    raise InstallStepError(
InstallStepError: GrubInstaller failed with code 1