Comment 55 for bug 1091464

Confirmed on Lenovo Thinkpad 450s with Ubuntu 14.04.2 LTS x64.

Grub2 version 2.02~beta2-9ubuntu1.1 .

Original menu entry produced by os-prober:

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows Boot Manager (on /dev/sda2)' --class windows --class os $menuentry_id_option 'osprober-efi-40BC-A843' {
    insmod part_gpt
    insmod fat
    set root='hd0,gpt2'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 40BC-A843
    else
      search --no-floppy --fs-uuid --set=root 40BC-A843
    fi
    chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
  set timeout=10
fi
### END /etc/grub.d/30_os-prober ###

Custom menu entry which DOES NOT work

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
menuentry 'Windows Boot Manager (on /dev/sda2) [mod]' --class windows --class os $menuentry_id_option 'osprober-efi-40BC-A843' {
    insmod part_gpt
    insmod fat
    insmod search_fs_uuid
    insmod chain
    search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 40BC-A843
    chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
  set timeout=3
fi

Hoping for a resolution to make it into the ubuntu repositories. I've no great desire to flash BIOS, use a different bootloader, or of course change the boot order every time so Windows boots. Happy to provide any and all further info needed!