Re: XFCE--can't mount USB devices

["Ad L." <mrd.debiannews@gmail.com>]

(Suggestion)
check the mount options in /etc/fstab. For example, the lines for one
of the user-accessible partitions on my external hard drive looks like
this:
# "Resources" partition on external HD (/dev/sdd2)
UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /mnt/Resources.src ext4
user,noauto,relatime 0 0

Note the option "user", or the alternative option "users". One of both
has to be there to be able to mount and unmount the filesystem without
root privileges.

Also note that "user" implies the restriction that only the user who
mounted the filesystem can unmount it again.