My android tab don't support Directional light ?

i use HCL ME U2 tab,and unity 3d 4.2 , i create new project and Scene ,the Scene contain only Terrain(withe tree,plants and some textuar),Main Camera,Directional light

then instal apk to my device,the game is full dark no light effect, i change my steeting to Auto rotate mode, then i rotate my device ,the light effect is work only period of rotation, after rotation it will go back to full dark no light effect work.

plz help me...