I can't find the documentation for GL_FIXED (as used in http://www.opengl.org/wiki/GLAPI/glVertexAttribPointer)?
Looks like it was added in GL 4.2 core for compatibility with OpenGL ES 2 (though... I don't think GL_FIXED has been a fast path since the original OpenGL ES 1.x devices).
Here's the original spec, from OpenGL ES:
And here it is as an ARB extension: