boot from ISO doesn't work

[DimmuBoy]

Hello there,
I seek to add entry boot from ISO, but nothing does work.

I tried it using burg-manager and editing of config file "/etc/burg.d/50_iso"

menuentry "BackTrack 5 x64 ISO" {
loopback loop (hd0,7)/dimmuboy/Install/Others/bt5_gnome-64.iso
linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=/dimmuboy/Install/Others/bt5_gnome-64.iso noprompt
initrd (loop)/casper/initrd.lz
}

but no one method doesn't work.

btw always I used update-burg and in burg-manager entry is displayed