usb mount

I have installed volumio this morning on raspberry pi but I have som usb issues
have a usb card with 3 partitions.
volumio mounts all 3 partitions on the same directory ?!?!?
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/sdb1 5.7G 1.8G 4.0G 31% /mnt/USB
/dev/sdb3 5.7G 1.8G 4.0G 31% /mnt/USB
/dev/sdb2 5.7G 1.8G 4.0G 31% /mnt/USB

Is this normal? I only see the content of sdb2 and the music is of course in sdb3…
I tried to disable usbmount automatount in usbmount.conf and fstab but still all three partiions get mounted on /mnt/USB
How can I solve this?
I least how to I disable usb automount so that I can mount partition with fstab?

Thank you

Mount manually your drive(s) somewhere else and symlink to /mnt/USB so everything will be there visible for Volumio.

The magic seems to happen in /etc/udev/rules.d/11-media-by-label-auto-mount.rules if I understand correctly, commenting out the right line there should prevent the auto mounting.