I have a 64-bit processor on a Dell 9360 machine.
If I boot into Knoppix 8.2.0 Live from a portable drive and run simple queries as follows I get:
$ lscpu
Architecture: x86_64
CPU op-mode(s): 32 bit,64 bit
Flags: ... lm ...
$ lshw -C processor | grep width
width: 64 bits
$ grep flags /proc/cpuinfo | grep " lm "
Flags: ... lm ...

which all confirm the 64-bit architecture. BUT the response
CPU op-mode(s): 32 bit,64 bit
apparently indicates that I am running a 64-bit-capable machine in 32-bit-mode.
Yes? - is this a true interpretation?
My /boot/isolinux/isolinux.cfg file contains the lines (omitting redundant qualifiers for ease of reading)
DEFAULT fergus
LABEL fergus
KERNEL ifcpu64.c32
APPEND knoppix64 -- knoppix
APPEND knoppix64
LABEL knoppix
KERNEL linux
APPEND initrd=minirt.gz
LABEL knoppix64
KERNEL linux64
APPEND initrd=minirt.gz

which I hoped meant "if 64-bit machine use 64-bit OS; if 32-bit machine use 32-bit OS" but apparently not.
How can I tweak the isolinux.cfg file to behave as required one line up?
Thank you!
PS1 I have to admit (I have only just noticed) that the file ifcpu64.c32 referred to above is very suggestive of an instruction "if 64-bit machine use 32-bit OS". Is that what it achieves, and the cause of the mismatch described?
PS2 I use this ifcpu file from the Knoppix 7.4.2 provision. I find the Knoppix 8.2.0 version stops Knoppix stone dead before it even starts. It simply does not work, at all. Anybody else?