Usb boot knoppix

Hello!!!
I'm trying to boot 2 live distribution backtrack 3 e knoppix 5.1.1 on a usb drive...
I made the first partition for boot loader grub that point to 2 other partition where are the 2 live...
I copied the knoppix's files by mounting the cd iso and copying the content on the pen drive...
The problem is what knoppix after loading the kernel starts hardware detection and i receive an error...
Accessing KNOPPIX cd at /dev/sda3...
Found primary KNOPPIX compressed image at /cdrom/KNOPPIX./KNOPPIX/bin/ln: cannot remove '/sbin':read only file system
/linuxrc: cannot create /etc/ld.so.cache: read only file system

When knoppix have to detect the usb device these run from sda to sdz and i receive an error:

Can't find KNOPPIX filesystem, sorry.
Dropping you to a (very limited) shell.
Press reset button to quit.

This is the part of menu.lst of grub about knoppix:

title Knoppix 5.1.1
root (hd0,2)
kernel /boot/isolinux/linux root=/dev/ram0 init=/etc/init lang=it apm=power-off vga=791 nomce quiet BOOT_IMAGE=knoppix ro quiet splash
initrd /boot/isolinux/minirt.gz
quiet

I don't understand what's the error...
I hope you can help me...
Thank you!!!

On this forum there details for grub booting the .iso without having to unpack it. Try that. Other than that try putting the files in a directory closer to root. Eg. /linux

Hello!!!
The solution is herea http://www.knoppix.net/wiki/USB_Based_FAQ
Those are the grub's options menu.lst:

Code:

---

title          Knoppix
kernel          /boot/isolinux/linux ramdisk_size=100000 init=/etc/init lang=us apm=power-off vga=791 initrd=minirt.gz nomce quiet BOOT_IMAGE=knoppix
initrd          /boot/isolinux/minirt.gz
boot

---

Thank you!!!