Need some tips to get URR to boot over PXE

I really prefer PXE to using live CD/USB for this kind of thing and I have a bunch of special purpose distros and installers set up this way. My inital attempt to set up URR for PXE booting on my server has gone like so:

copy RescueRemix iso contents to a subdir (RescueRemix) in my netboot folder, create a submenu to boot the casper/vmlinuz
[code]
MENU LABEL Ubuntu Rescue Remix
KERNEL RescueRemix/casper/vmlinuz
APPEND boot=casper netboot=nfs nfsroot=: -o nolock initrd=RescueRemix/casper/initrd.gz
TEXT HELP
Boot into URR recovery and forensic environment
ENDTEXT
[/code]
It chokes on not being able to mount /cdrom during boot and then crashes with the text "[initramfs] Unable to find a live file system on the network" There surely must be a way here, this is linux after all. I'm stumped though.