If you plug in a USB Stick at the terminal, there is no window, which opens automatically.
Plugged in USB sticks or ext. hard drives will appear in your home directory under the folder thindrives.
Open a Filemanager (Menu: Places) and navigate to your 'home directory > thindrives'.
- Mount and unmount happens automatically - wait a few seconds.
If you copy data, wait until the light on the USB stick stops flashing or the progress bar disappear, plus some additional seconds. After that, it's secure to remove the stick.
If the stick does not appear under directory '~/thindrives', please trigger a remount via menu Repair thindrives (USB Stick , ...).