The red square is not centered because that block is not finished yet. Someone needs to add another strip to the bottom and left sides. :)

[QUOTE=Peckish;7317703]The red square is not centered because that block is not finished yet. Someone needs to add another strip to the bottom and left sides. :)[/Q

You are right -

OR - take off a strip from the top and right side :)

Thank you - that was really bugging me - and the solution was so obvious!