On your #15 reply above I see you have managed to sort the problem. In very much layman's terms how do you do this.
Okay, this is at your own risk. Do you trust Airnav's site!!
In IE8, select TOOLS - INTERNET OPTIONS
Select the SECURITY tab
Click on TRUSTED SITES
Click on the SITES button
Untick the "Require Server Verification" tick-box
Add
http://www.airnavsystems.com to the list of trusted sites