Crash during fresh installation over Win 8.1

[Anders Ekberg]

Crashed when installing

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubiquity 2.18.8
ProcVersionSignature: Ubuntu 3.13.0-30.54-generic 3.13.11.2
Uname: Linux 3.13.0-30-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
CasperVersion: 1.340
Date: Thu Jul 3 17:14:45 2014
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash --
LiveMediaBuild: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140702)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Foundations Team Bug Bot (crichton)]

Exception during installation:
Jul 3 15:13:04 ubuntu /plugininstall.py: Traceback (most recent call last):
Jul 3 15:13:04 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 1770, in <module>
Jul 3 15:13:04 ubuntu /plugininstall.py: install.run()
Jul 3 15:13:04 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 78, in wrapper
Jul 3 15:13:04 ubuntu /plugininstall.py: func(self)
Jul 3 15:13:04 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 221, in run
Jul 3 15:13:04 ubuntu /plugininstall.py: self.remove_unusable_kernels()
Jul 3 15:13:04 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 801, in remove_unusable_kernels
Jul 3 15:13:04 ubuntu /plugininstall.py: self.do_install(install_kernels)
Jul 3 15:13:04 ubuntu /plugininstall.py: File "/usr/lib/ubiquity/ubiquity/install_misc.py", line 912, in do_install
Jul 3 15:13:04 ubuntu /plugininstall.py: mark_install(cache, pkg)
Jul 3 15:13:04 ubuntu /plugininstall.py: File "/usr/lib/ubiquity/ubiquity/install_misc.py", line 527, in mark_install
Jul 3 15:13:04 ubuntu /plugininstall.py: "Unable to install '%s' due to conflicts." % pkg)
Jul 3 15:13:04 ubuntu /plugininstall.py: ubiquity.install_misc.InstallStepError: Unable to install 'linux-signed-generic' due to conflicts.
Jul 3 15:13:04 ubuntu /plugininstall.py: