According to one embodiment, there is provided a high voltage isolation dual capacitor communication system comprising communication drive and sense electrodes and corresponding first and second capacitors that are formed in two separate devices. A user authentication to judge a properness of a user of the mobile computer is carried out according to a user input based information, and the current location of the mobile computer is registered at the mobile computer management device when the user is judged as a proper user. Methods for using the platinum compounds, either alone or in combination with at least one additional therapeutic agent, in the prophylaxis or treatment of proliferative diseases. A second elongate upper post section has the lower end thereof connected to the upper end of the first post section by a second slip type coupling.