chroot: cannot run command `/bin/bash': Exec format error

[debiminho]

Hello,
Im trying to make a chroot like

root@Knoppix:/# chroot /mnt/hda2
chroot: cannot run command `/bin/bash': Exec format error

Wy this is not working out of the box ? Debootstrap don't work because of this....
I Search in the google and blablablbla nothing conclusive, first time i have problems
with knoppix, im using the version 5.1...

Thanks in advance.