a new install of Knoppix on a hard drive worked well, except I could not open a memory stick;
temporary fix: open console;
su (enter root password) mkdir /media/usbdisk
mount /dev/sda1 -t auto /media/usbdisk
permanent fix: edit fstab;
how to? open console: type kdesu kwrite /etc/fstab (enter root password at prompt)
alter final line to /dev/sda1 /media/sda1 auto noauto,users,exec,umask=000,uid=username,gid=users 0 0
save
the system now reads a memory stick fine

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