crashed when installing ubuntu 13.04 inside VirtualBox

[NIXin]

Default installation of Lubuntu, crashes when setup to use automatic partitioning with encrypted LVM.
No other changes to the installation settings.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: ubiquity 2.14.1
ProcVersionSignature: Ubuntu 3.8.0-16.26-generic 3.8.5
Uname: Linux 3.8.0-16-generic x86_64
ApportVersion: 2.9.2-0ubuntu5
Architecture: amd64
CasperVersion: 1.330
Date: Sat Apr 20 14:53:34 2013
InstallCmdLine: file=/cdrom/preseed/lubuntu.seed boot=casper only-ubiquity initrd=/casper/initrd.lz quiet splash --
LiveMediaBuild: Lubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130403)
MarkForUpload: True
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 LANG=en_US.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[NIXin (nixin)]

I will just add the same thing happened to me trying to install Ubuntu, without LVM, and without encryption.
So it's either a generic problem, or a compatibility problem with Oracle's VirtualBox (forgot to mention that).

[Ubuntu Foundations Team Bug Bot (crichton)]

Exception during installation:
Apr 20 12:53:16 lubuntu /plugininstall.py: Traceback (most recent call last):
Apr 20 12:53:16 lubuntu /plugininstall.py: File "/usr/lib/python3/dist-packages/apt/progress/text.py", line 146, in fetch
Apr 20 12:53:16 lubuntu /plugininstall.py: line += (" [%sB]" % apt_pkg.size_to_str(item.owner.filesize))
Apr 20 12:53:16 lubuntu /plugininstall.py: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa0 in position 1: invalid start byte
Apr 20 12:53:16 lubuntu /plugininstall.py: