Just an update.
Mine is still with the same issue... As Steve said, hidden shares in Windows use the $ at the end of the share name... And there was no issue mounting this kind of shares using the plugin, until recent updates.
Since it stoped working, the error was "-- Invalid Configuration - Remove and Re-add --". I've updated the plugin now and the error changed to "Device '//192.168.0.95/share' failed to mount. Check the syslog for details."
About the "ghost" mount, I tried "umount /mnt/remotes/share" and it worked, but the root folder for the share is still there...
Thanks!