ubiquity crashes on various stages of the installation

[nk8215]

Firstly I tried to install Oneiric Ocelot (Ubuntu 11.10) on my newly acquired external HDD by manual partitioning (since I wanted to keep my MS Win7 setup on the internal HDD intact). ubiquity crashed at the GRUB installation ("execution of "grub-install /dev/sdb5 (the partition, which I reserved for the /boot directory before)" failed, please select other device to install the bootloader", therefore I decided to make rather a side-by-side installation - however, this time ubiquity crashed at the partitioning phase.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: ubiquity 2.8.7
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic i686
ApportVersion: 1.23-0ubuntu3
Architecture: i386
CasperVersion: 1.287
Date: Thu Nov 17 13:17:51 2011
LiveMediaBuild: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
ProcEnviron:
 LANGUAGE=de_DE.UTF-8
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[dino99 (9d9)]

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