Even simplier than that.
1: Boot Knoppix without Sandisk Crizer

2: become root Ctrl-Alt-F2

3: echo /sbin/hotplug > /proc/sys/kernel/hotplug

4: mount /dev/sda1 /mnt/test
On some machines:
mount /dev/sdb1 /mnt/test

The real culprit is /sbin/hotplug-knoppix which does something that causes a system to lock-up hard way.
The original /sbin/hotlug (also included in KNOPPIX) works fine.

AZ