Alfa Handbrake failure

Has any other Alfa 156 owner had their car relocate itself down steep hills? Mine rolled 50 metres last week. I've heard the electronic testing takes place every 6 seconds and while testing the gears are disengaged and the hand brake won't take effect. Hence over two hours my car slipped away and parked itself on a neighbours lawn! In the past two weeks, this has happened and the A/C is not cold and the temp. is diddling around - is this a computer/electronic problem? It is a devine black with red momo leather, remaro(?) interior and full monza kit - I love it dearly but not enough to not finding it in the dark! Please respond - I have Alfa Romeo - Brisbane - Queensland - Australia looking at it in 15 hours and would like to be prepared to ask good questions! Otherwise they're going to treat me like a typical female driver and no doubt will be dupped! Thanks for any insights.