From bad experiences (not mine) with grub not being able to run on corrupted journaling file systems, I have come to the conclusion that whenever possible, I should heed the old advice and create a separate boot partition, also on usb-sticks etc.
If we place that partition at the "end" of the stick, it is not disturbing much, so here's what I do:
1. I typically create a N-0.3 GB first partition, and a 0.3 GB boot-partition on the stick.
2. Format the boot-partition with ext2, the other with anything usable.
3. Mount the boot partition.
4. Next, install grub on the MBR of the stick and the boot-partition
Code:
grub-install --root-directory=/media/sdb2 /dev/sdb
5. Create a boot subdirectory, and copy over the Knoppix boot files from /mnt-system/boot/syslinux - I assume you are running from a version with correct boot-directory:
Code:
mkdir /media/sdb2/boot/knx644
rsync -ax /mnt-system/boot/syslinux/ /media/sdb2/boot/knx644
6. Create a suitable menu.lst file with boot entries first for the stick, e.g.
Code:
default=1
timeout=10
title Knoppix 6.4.4 all arch
kernel (hd0,1)/boot/knx644/linux ramdisk_size=100000 lang=en keyboard=no fromhd=/dev/sdb1 nosound vt.default_utf8=0 apm=power-off initrd=minirt.gz nomce libata.force=noncq loglevel=1 tz=localtime
initrd (hd0,1)/boot/knx644/minirt.gz
title Knoppix 6.4.4 64 bits
kernel (hd0,1)/boot/knx644/linux64 ramdisk_size=100000 lang=en keyboard=no fromhd=/dev/sdb1 nosound vt.default_utf8=0 apm=power-off initrd=minirt.gz nomce libata.force=noncq loglevel=1 tz=localtime
initrd (hd0,1)/boot/knx644/minirt.gz
Note that the correct init parameters may vary with release, I was quite confused when booting 6.4.4 with the seemingly innocent 6.2.1 init line gave different strange errors on booting, leading me to suspect file corruption. Copy the actual APPEND line from syslinux.cfg and edit.
One nice thing with this setup, is that you don't have to reinstall the booting machinery for booting other OS versions, devices etc. Just add subdirectories under /boot with the correct files (when necessary), and edit the menu. Just varying minirt.gz (one per directory) is a simple and safe way of experimenting with different system setups.
AFAIK, this simple editing is not easy with grub2. So I can't regard that version as neither grand nor unified. But bootloader, maybe yes.