How to distribute lines connected between blocks

OmniGraffle OmniGraffle for Mac
#1

I have two boxes and would like to have two lines between them distributed evenly. The first line I create is connected to the center of the box (I know how to create magnets). I then create another line next to it.

Unfortunately, both those lines are not distributed evenly (the center line has to move). How do I distribute the two lines? Here is a screencapture to explain this better: http://s3.amazonaws.com/pr12/screencapture_omnigraffle_box.mp4

#2

why not add more magnets (in the position you want the lines to be) to the shape? You can use the magnet tool from the toolbar for that.