navigation-splirt screen-exitwindow issues

[bcs]

I have X5 3.0d E70, model from 2009.
the navigation system in the begining worked fine but i had issue a month ago with split screen.( working with 2009-1 dvd)
When i did the exit assist window , the navigation system would take up the full screen .

now i have only in the main screen which is about half the screen.
but the radio and the climate screen worked in full screen.
i complained to bmw and they did some upgrade..now it has gone worst ..forget the navigation screen even the radio screen works only in half screen.
upon enquiring they started to wonder if it ever worked in full screen in the first place.

so i need some proof for them that it worked...could any body out there..help me?..or anybody has a similar issue...any body got it solved