I'm running 3.6 from ramdisk using toram install option.

Go to knoppix menu in kde and open root shell. Run passwd command to change
root's password. It reports that the password was successfully updated.

Open a separate terminal as user knoppix. Say "su -", expecting to be asked for root
password. It goes straight to root id without asking me for the password.

What do I need to do to fix this?