why 2.1.4 DrawPrimitivesTest's "ccPointSize(64);" can't work?????

cocos2d-x C++
#1

i found the code " s_nPointSizeLocation = glGetUniformLocation( s_pShader~~>getProgram, “u_pointSize”);"
in “static void lazy_init( void )” function, the s_nPointSizeLocation will get~~1, so i can’t find u_pointSize’s location.
i don’t know why,because on other pc,s_nPointSizeLocation will get the right result.
my video card is ati x1200!
so some one can help me , very thanks