Is there a reason for two layers of blue lines editmode? If it doesn't serve a purpose I'd recommend removing it; while it won't help framerates during games, and reduction in the number of calls to glVertex in editmode.
http://oi56.tinypic.com/2guxzz5.jpg
Having uploaded the image it even looks like the blue line branches off into a third at the left side.
http://oi56.tinypic.com/2guxzz5.jpg
Having uploaded the image it even looks like the blue line branches off into a third at the left side.