Detection of USB flash drive by pamusb

[PenguinNurse]

Dear Ubuntu community,

The command
sudo pamusb-conf --add-device my_usb_pen only detects my hard disk and not my mounted flash pen with vfat (also tried ext2, ext3 and ext4) file system, in order to use it for USB authentification.
What additional diagnostics could I run to pin down the problem?

Thanks in advance for your help!

[PenguinNurse]

By using
sudo pamusb -v --add-device="MyStick" I was informed about a missing volume on the stick.
By using gparted, I was able to fix the problem.
However, after using
sudo pamusb-conf --add-user="me",

pamusb-check me tells me

* No device configured for "me".
The file /etc/pamusb.conf seems to be correct.