[arch-releng] Iso booting

[Mr Green]

Have an odd problem, trying to boot an iso from grub2 using

menuentry "Archlinux-2011.08.19-netinstall-x86_64.iso" {
     set isofile="/iso/archlinux-2012.07.15-netinstall-dual.iso"
     loopback loop (hd0,1)$isofile
     linux (loop)/arch/boot/x86_64/vmlinuz archisolabel=ARCH_201207 
img_dev=/dev/sda1 img_loop=$isofile earlymodules=loop
     initrd (loop)/arch/boot/x86_64/archiso.img
}

menuentry "ArchBang" {
     set isofile="/iso/archbang-2012.07.26-x86_64.iso"
     loopback loop (hd0,1)$isofile
     linux (loop)/arch/boot/x86_64/vmlinuz archisolabel=ARCHBANG 
img_dev=/dev/sda1  img_loop=$isofile  earlymodules=loop
     initrd (loop)/arch/boot/x86_64/archiso.img
}

The first menuentry works fine but ArchBang refuses to boot, both are in 
the same directory on the same disc.

Odd thing is that /dev/disk/by-label is not created in Archbang, both 
isos have the same hooks loops, tried with latest archiso from git but 
no joy.

Can anyone shed any light on the problem?

MrG