Attempting to install ubuntu 12.04 to a sony vaio z11 fails when trying to install the bootloader, installer crashes

[Peter Rhone]

i am attempting to install ubuntu 12.04 onto my sony vaio z11, but bootloader installation fails when trying to install to /dev/mapper, and when I try to exit the installer to install the bootloader manually, the installer crashes.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: ubiquity 2.10.16
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic x86_64
ApportVersion: 2.0.1-0ubuntu5
Architecture: amd64
CasperVersion: 1.315
Date: Wed May 30 21:54:50 2012
InstallCmdLine: noprompt cdrom-detect/try-usb=true file=/cdrom/preseed/ubuntu.seed boot=casper persistent initrd=/casper/initrd.lz splash -- BOOT_IMAGE=/casper/vmlinuz
LiveMediaBuild: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
ProcEnviron:
 TERM=unknown
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)