Shader not working when using VBO in some computers

bugs, errors
#1

Hi!

I am having trouble with VBOs and shaders in some computers and I am quite lost on why this is happening. Particularly, I managed to reduce the problem to a minimal example that works in one computer and not in another one.

vertex shader:

#version 120

void main(){
    gl_Position = gl_ProjectionMatrix * gl_ModelViewMatrix * gl_Vertex; // == ftransform()
    gl_FrontColor = gl_Color;
}

fragment shader:

#version 120

void main(){
    gl_FragColor = vec4(0,1,1,1);
}

Then we basically build an ofVbo with vertex and index data. And draw it using drawElements between a begin and end of the ofShader. It is pretty clear to me that anything drawn at this point should be cyan.

The result on OSX 10.8.5 ,Nvidia geforce 9400M 256MB:

good.png1034×531 37.3 KB

The result on OSX 10.10.3 Intel HD Graphics 3000 384MB:

bad.png1032×528 34 KB

I have no idea if this is a bug or I am doing something wrong here. Any Idea?
Complete code: https://github.com/chaosct/VBO_OF_bug