1. Uninstall the Host. 2. Open Windows registry, locate the key "HKEY_LOCAL_MACHINE\SYSTEM\Remote Utilities" and wipe/delete it. 3. Install the Host again, preferably the oldest version available in the sticky. 4. Reboot the machine.
The log on/log off feature acts like the stand-by mode on a TV set. That is, you can "log on" to the remote PC meaning that you keep the connection alive while not using any specific connection mode.
When you are in the Full Control mode (or any other mode for that matter), by clicking on the X button in the mode window, you close that specific connection mode. But you are still being "logged on" to the remote computer. In order to disconnect completely, just click "Log off" either on the Viewer toolbar or in the context menu of the target remote connection in your address book.
You can also use the Log Off command right away in which case all open connection modes will automatically close.
Hope that helps. Don't hesitate to ask if you have any questions.