In Technical FAQ 9.030 (http://www.opengl.org/resources/faq/technical/transformations.htm#tran0030) it says:
"If exact pixelization is required, you might want to put a small translation in the ModelView matrix, as shown below:
glTranslatef (0.375, 0.375, 0.);"
As far as my understanding goes, the OpenGL rasterization rules define texels and pixels to already be aligned perfectly.
So this should actually be exactly the wrong thing to do.
I would suggest this part to be removed.