Cycles Viewport render ( Shift + Z ) is much brighter than final render I am new to Blender and this was my first project. I got the lighting to look ok in the viewport render preview (Shift + Z ) but then i do the final render ( using cycles) it is incredibly dark.
Viewport:


and final render :


I have tried rendering on GPU and CPU with the same result. 
As this is the first time i've ever used Blender, it's probably something stupid, but any help would be greatly appreciated. Thank you.
Your area lamp is disabled for render (last icon on the first line):