I'm just using the opengl SDL template with Xcode, and everything runs fine. I removed the Atlantis code, and changed the main extension to .mm, then added some testing code to drawGL. Drawing a simple triangle (using immediate mode) at this point inside drawGL gives me a white triangle, but when I add the code to draw using a vertex buffer object, i just get a black window.

Here is my VBO drawing code:

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);     // Clear The Screen And The Depth Buffer
glLoadIdentity();

GLuint buffer;

float vertices[] = {
    0.0f, 1.0f, 0.0f,
    -1.0f,-1.0f, 0.0f,
    1.0f,-1.0f, 0.0f
};

// VBO doesn't work :(
glGenBuffers(1, &buffer);
glBindBuffer(GL_ARRAY_BUFFER, buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 9, vertices, GL_STATIC_DRAW);

glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, vertices);
glDrawArrays(GL_TRIANGLES, 0, 3);
glDisableClientState(GL_VERTEX_ARRAY);