Remastered Knoppix as host for Qemu Guests

Hi everybody.
I'm writing to search for help about a problem i'm experiencing.
I'm using knoppix as host system for a virtualized computing-grid testbed, implemented as two Scientific Linux (RHEL like) guests launched by the qemu emulator.
Two scenarios follow:
1) I boot a Knoppix "vanilla" system (which get access, when ready, to the local disks). As the system become ready, I install qemu, uml-utilites,bridge-utils (via apt-get), and I run qemu to virtualize two pre-installed Scientific Linux images (laying on my main physical disc). Everything goes ok.
2) I remaster Knoppix to include qemu/bridge-utils/uml-utilites and the two SL images. When finished, I restart the whole system and boot from the new, remastered, knoppix DVD. When the booting phase ends, I try to launch my qemu-ed images. Both of the images, when trying to chroot to /, fail with a bad kernel panic.
Does someone know what is the reason for this to happen? Why this behaviour difference within the two previous environments?
Thank you in advance,
Alex.

N.B: Sorry for the crosspost, but i really don't know if this one is the correct forum for my post.