When multidisk btrfs volume is available in system, thunar display volume name many times (as many as number of disks in btrfs). Here small preview of thunar with 8 disk btrfs file system named 'JBOD': http://s15.postimg.org/8nrgkzerf/thunar.png
Actually, Thunar get the disks from udisks/udev so it might be worth checking what happens there, maybe those kind of disks need a UDISKS_IGNORE udev rule or something. Regards,