Let ther be... uhh... light?

So yesterday evening I decided to try and make the house look a little more festive by stringing up some lights around the eve of the roof. How hard could it be? It was just two strands, totaling 800 little white lights. I tested them and they all worked, I had a ladder, a staple gun, and a lovely assistant. Once it was all in place, we plugged it in, and... one section of about 50 lights was out. Long story short, I need to cut my losses and just pull it all down and try again. Pure joy.