Nvidia Geforce 6150 Multiple Monitors Dualview Issue on HP Pavilion tx2001au

Nvidia Geforce 6150 Multiple Monitors Dualview Issue on HP Pavilion tx2001au

I have a Nvidia Geforce 6150 card on my Laptop - HP Pavilion tx2001au Entertainment Notebook PC . I attached a LCD monitor to my Laptop..I am not getting display on second monitor in dualview mode (extended desktop) .However,on Clone Display mode i get display on both the laptop monitor and the external display. Whats the issue ?