LinuxQuestions.org - my flash drives somehow got mounted as network shares--I think

I seem to have a little problem I've never seen before; I must have caused it by some error, but I have no idea how. My two backup flash drives appear to be mounted twice, once in the correct location and once as..."connected"--uh, does that mean the system thinks they're network shares? Sorry, I barely know whether that's the correct term. Screenshots attached.

The only practical problem so far is that the backup schedule in Luckybackup is disrupted: Luckybackup kept saying the flash drives weren't mounted, when they were. I finally unmounted and remounted them, and that allowed backing up to proceed when I manually started the backups. Whatever caused the flash drives to show as "connected" in Thunar, I keep trying to disconnect them (without knowing what they're even connected to), but as you can see in screenshot #2, it won't let me disconnect them--"operation not permitted." I don't know whether I'll have to do that all over again the next time I reboot and everything gets mounted.

I did edit fstab recently. I don't know of any error I could make there that would cause this, but if anyone would like to see it:

Code:

# Pluggable devices are handled by uDev, they are not in fstab

UUID=103c0db4-af2c-45d2-9f8d-8d25d2a6ed72 / auto defaults,noatime 1 1

#        -LINUXB

#UUID=8e890c3d-033b-4de8-8bcf-9ea50b6900d6 / auto defaults,noatime 1 1

#        -LINUXA

UUID=ac4c8712-421f-48ef-a631-ddec0301f3ca /home auto defaults,noatime 1 2

/dev/sda1 /media/DATA auto defaults,noatime 1 1

/dev/sda2 /media/MUSICANDSTORAGE auto defaults,noatime 1 1

UUID=eb63fb90-27c0-41bc-9886-aa2526340c24 /media/HOMEBACKUP auto defaults,noatime 1 1

#        -HOMEBACKUP

UUID=a42f7ad3-7dc7-4559-9451-07c5a96afecf /media/DATABACKUP auto defaults,noatime 1 1

#        -DATABACKUP

UUID=FA8A-B61D /media/CLIPJAM auto defaults,noatime 1 1

UUID=3136-3834 /media/MUSICMEMCARD auto defaults,noatime 1 1

# Added by make-fstab /dev/sda5  label=MXswap

UUID=550ce11c-e33c-47ed-84ec-e021d0aaa087  swap                                        swap      defaults                        0