All,
For the time being all is OK - apart from a scare yesterday when the files stopped jumping around, but this time I didn't loose any data when I quit and restarted the software (watching a live stream was probably the reason why it slowed down).
There is however a positive point from all this - Since I have changed the installation from the default installation to installing in c:\Airnav (as recommended by tarbat) the windows are acting much better, or normally.
Before, when you had the Db or MyLog windows open - on top of the main software window - when you went to another window, in my case Firefox on a second screen, it kept closing the window. Now it stays open as you would expect. Also, when the main program window was maximized it wouldn't except another window on top of it. Now it does.
Unfortunately there is a small negative point with the Map Colours. On the map view it's impossible to change the background colour of Terrain>0ft. It indicates black on the elevation list under Preferences, Map Colors, but it's the same colour as the sea (blue) on the map view. It wasn't like that before.
Andrew