iOS OpenGL - Ambient light working in simulator, not on device.

        glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);     	     

	GLfloat ambient[] = {0.6, 0.6, 0.6, 1.0 };
	GLfloat diffuse[] = { 1, 1, 1, 1 };
	GLfloat specular[] = { 0,0, 0, 1.0 };

	glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
	glLightfv( GL_LIGHT0, GL_SPECULAR, specular);

	GLfloat position[] = { direction.x, direction.y, direction.z, 0.0 };
	glLightfv(GL_LIGHT0, GL_POSITION, position);

		GLfloat amb[] = { 1,1, 1, 1.0 };
		GLfloat diffuse[] = { 1, 1, 1, 1.0 }; 	
		glMaterialfv(GL_FRONT, GL_AMBIENT, amb);
		glMaterialfv(GL_FRONT, GL_DIFFUSE, diffuse);

	float lightAmbient[] = { 0.3f, 0.3f, 0.3f, 1.0f };
	float lightDiffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };

	float matAmbient[] = { 0.6f, 0.6f, 0.6f, 1.0f };
	float matDiffuse[] = { 0.6f, 0.6f, 0.6f, 1.0f };

	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);     	     

	glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, matAmbient);
	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, matDiffuse);

	glLightfv(GL_LIGHT0, GL_AMBIENT, lightAmbient);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, lightDiffuse);


	//using my vector class
	direction.unit();	
	GLfloat position[] = { direction.x, direction.y, direction.z, 0.0 };
	glLightfv(GL_LIGHT0, GL_POSITION, position);