Comment 12 for bug 1172065

I have a few more details to share.

Mounting the iso under windows 8 displays the same incorrect filename, as does burning the iso to physical media under windows 7.

So to me, it would appear that anyone unlucky enough to use the ubuntu-12.04.3-desktop-amd64.iso under windows 7/8, whether it be to:
a.) physically burn it to disc;
b.) mount it virtually;
c.) create a USB boot system from it
would be unable to successfully install ubuntu 12.04.3 LTS on an UEFI booted system.

During installation of grub, the installer throws the error "'grub-efi-amd64-signed' package failed to install into /target/. Without the GRUB boot loader, the installed system will not boot."

Because the .deb file is misnamed, the following is reported in syslog during installation:
Dec 4 17:41:36 ubuntu ubiquity: E: Unable to locate package grub-efi-amd64-signed

Workarounds:
===========
If you are creating a bootable USB on Windows 7/8, rename the misnamed file after the USB has been written so that the installer does not error out during installation.

Alternatively, since the file is not misnamed in linux, using the iso to burn a USB boot system from within linux will also likely work.

From what I can gather so far, Boot-Repair seems to be the current mechanism used to resolve problems that result from this, since Boot-Repair first removes grub and then re-installs it.
WARNING: (For those of you that may have arrived here from a Google search) Boot-Repair downloads the grub packages from the Internet, so be sure to have a fully functioning Internet connection if you use this method. If Boot-Repair doesn't find an Internet connection, you will be warned that your system may be left in an unbootable state. Heed this warning, because while apt will happily remove grub without one, it cannot download and re-install grub without a connection to the Internet.