Suacy install fails to install bootloader

I'v been trying to install Saucy on a btrfs file system. This latest attemp was with /boot mounted on vda1 ext2. I previously have tried to install to btrfs raid1 made up from /dev/vda1 and /dev/vb1. I'm not sure if the problem is with btrfs or kvm.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: ubiquity 2.15.26
ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
Uname: Linux 3.11.0-12-generic x86_64
ApportVersion: 2.12.5-0ubuntu2
Architecture: amd64
CasperVersion: 1.336ubuntu1
Date: Mon Dec 30 17:20:43 2013
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash -- maybe-ubiquity
LiveMediaBuild: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)