Ok I guess sxb stacker can't be installed as a loopback, but sxb new isn't working either. I've followed the directions. On my E partition I have these three directories:
sxbloop - contains sxbloop.img
sxbox - contains sxb iso contents minus initrd.gz, renamed linuxbloot.cfg.hd and vmlinuz
sxboxE - contains initrd.gz, renamed linuxboot.cfg.hd vmlinuz and swap.img
When I load sbxbloop-e from the boot menu I get "kernel panic: VFS: Unable to mount root fs on 07:00."