Er, if you increase the light and/or remove fallof, you don't get the shadows on the edges. Almost the same if you click Infinite Light. then, I created a parallel light 20x20x20. Intensity 25, Soft edge 50. Used the default gradient, Linear fallof and Infinite checked. Strung five lights on 5 BU difference. IE, the first one on 0, second on 5, third on 10... No edges inside - one rectangular light trail with fallof at the edges. Unfortunately, the light looks like there are two light bulbs at the positions of lights one and five. But the lighting difference is really not that noticeable. the main problem is that parallel light has a strong light source in the centre. BTW, try positioning parallel light above the horizon line, checking infinite and volume, and see what happens when the ray intersects the horizon. :-) Totally weird. Sorry, no pics, my Photoshop is still kaput.

-- erlik