AutoCAD Inventor :: Rectangular Pattern With 2 Curve Lengths - 1 Sketch

I would like to use a sketch as the basis for a rectangular pattern which is set up to use the curve length for both directions of the rectangular pattern so that when I update my rectangle in a sketch, the pattern automatically adjusts to the new sketch. I have sketched a rectangle, and used one leg of the rectangle to establish the direction and length of one dimension of the array.            

However, when I try and choose the Direction 2, my only options are the entire rectangle or faces- I can no longer select other and choose a single side of the rectangle.

I was able to accomplish what I wanted by using two sketches, with the second sketch simply projecting one leg from the first sketch.  Using one sketch just seems inherently safer than trusting projected geometry.Is there a way to accomplish this with one sketch instead?

Inventor 2013 (SP2 Update 2), Windows 7 Professional (64-bit), SP1, Intel Xeon 3.07GHz CPU, 12GB RAM, NVIDIA Quadro 2000, Vault Basic 2013