Hello,

the situation seems to be more tricky:

1. okay, my fault: I forgot to switch on the USB support in the BIOS.
2. the USB stick is still not recognized in my Knoppix 3.3 HDD installation after adding the line given above in the file /etc/fstab. My user account was already added to that group USB, I checked it with KUser. Then I made a new link to it with a new desktop icon. But when I click on it, the filesystem won't be mounted, but an error message is shown saying that there's no block device. And strangely: In the KDE Info Centre under USB, there's no USB device shown. But lspci shows that the USB port is there. I chose /dev/sda1 for the USB and /dev/sda4 is my Iomega ZIP 100 drive (works nicely). That's the situation on HDD.
3. Starting Knoppix 3.4 from CD however, the USB stick is recognized and in the KDE Info Centre under USB you can even see its serial number and the vendor name correctly. Thus, there's probably no hardware fault. But on the desktop, all /dev/sdax (x = 1-4) icons give error messages that the filesystem could not be detected.

What can I do???

Many thanks in advance for your kind help!

Oli