grub2 install fails installing to sda efi boot area?

[Pat Rick]

secureboot/ fast boot etc all turned off, ubuntu being installed on a secondary gpt disk, primary raid disk contains windows and boot manager, grub2 fails installing to sda boot area

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubiquity 2.18.7
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CasperVersion: 1.340
Date: Thu May 29 13:53:26 2014
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash --
LiveMediaBuild: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
ProcEnviron:
 LANGUAGE=en_CA.UTF-8
 TERM=linux
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_CA.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Foundations Team Bug Bot (crichton)]

Exception during installation:
May 29 19:53:04 ubuntu /plugininstall.py: Traceback (most recent call last):
May 29 19:53:04 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 1770, in <module>
May 29 19:53:04 ubuntu /plugininstall.py: install.run()
May 29 19:53:04 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 78, in wrapper
May 29 19:53:04 ubuntu /plugininstall.py: func(self)
May 29 19:53:04 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 241, in run
May 29 19:53:04 ubuntu /plugininstall.py: self.configure_bootloader()
May 29 19:53:04 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 1026, in configure_bootloader
May 29 19:53:04 ubuntu /plugininstall.py: "GrubInstaller failed with code %d" % ret)
May 29 19:53:04 ubuntu /plugininstall.py: ubiquity.install_misc.InstallStepError: GrubInstaller failed with code 1
May 29 19:53:04 ubuntu /plugininstall.py: