I have been attempting to get the Navigation system on my Axim 51 to work for three month. I have spent countless hours in chat with Dell tech line. They have replaced the basic unit twice now. Still the problem I get is when attempting to open the Navigator. I receive the message "The file DellNavVGA cannot be opened. It is either not signed with a trusted certificate, or one of its components cannot be found". Any suggestions? I have uninstalled and installed the software many times.