Thanks for your explanation, Fanoush. You just saved me from crashing my system!

I managed to find the solution you mentioned, which prevents the Linux desktop from automounting the IT root filesystem. For the record, here's the procedure.

The file to be modified (as root) is: /usr/sbin/osso-usb-mass-storage-enable.sh

1. add "DEVICE=${1}p1" at the beginning of the file after the comments.

2. replace all occurences of "$1" (about 5 of them) with "$DEVICE"

The solution was found here.