Comment 8 for bug 1170183

I too wound up with \EFI\ubuntu\grubx64.efi as a uefi boot entry on a machine which had always had secure boot enabled. This was caused by an earlier grub-install which left a corrupt /EFI/ubuntu directory, which gave an IO error on any attempted access. After fixing the corrupted directory, rerunning grub-install --uefi-secure-boot added a new, correct ubuntu/shimx63.efi entry. Looks like the error checking on grub-install might need a little improvement -- looks like a check for shim failed, but only because the directory itself was unreadable.