ubiquity crashed with InstallStepError in configure_bootloader()

Binary package hint: ubiquity

testing Karmic Alpha 2 installation.

My set-up:

two drives are RAID 0 with Windows:
sda
sdb

one drive is totally empty:
sdc

I'm installing onto sdc, and installing the bootloader on sdc. I've also tried installing the bootloader on (hd0), which would be the striped array - and this problem still exists.

I would try with the daily build CD, but I can't get it to load yet (alpha 2 loads but the daily builds won't).

I can install successfully using a 9.04 install CD.

ProblemType: Crash
Architecture: amd64
Date: Sun Jul 12 20:51:47 2009
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/lib/ubiquity/bin/ubiquity
InterpreterPath: /usr/bin/python2.6
LiveMediaBuild: Ubuntu 9.10 "Karmic Koala" - Alpha amd64 (20090624)
Package: ubiquity 1.13.4 [modified: lib/partman/automatically_partition/question]
ProcCmdline: /usr/bin/python /usr/lib/ubiquity/bin/ubiquity --only
ProcEnviron:
 LANGUAGE=
 PATH=(custom, no user)
 LANG=en_US.UTF-8
ProcVersionSignature: Ubuntu 2.6.30-9.10-generic
PythonArgs: ['/usr/lib/ubiquity/bin/ubiquity', '--only']
SourcePackage: ubiquity
Title: ubiquity crashed with InstallStepError in configure_bootloader()
Uname: Linux 2.6.30-9-generic x86_64
UserGroups: