I use Plop bootmanager's executable to boot all my usb stuff
it can boot usb, usb-cdrom,etc even on PC's that wont boot usb,etc
http://www.plop.at/en/bootmanager.html
I use this executable
named
plpbt<link
it doesn't install or anything
you just put it on cd, usb, hd, etc
and setup menu to boot it
example grub menu.lst for plop
Code:
title Plop
root (hdx,x)
kernel /boot/plpbt
example isolinux/syslinux.cfg entry
Code:
label plop
menu label Plop Bootmanager
kernel /boot/plpbt
I have it on most of my newer stuff
http://multidistro.com/downloads/newstuff/newstuff.html