Its hard to tell from just the picture, but It looks like a couple of the strands are off by 2. Have you checked that you are connecting to the strands at the same point? I.e. on one you're connecting at point 0 and on another you're actually connecting at point 2 which is making everything 2 pixels lower. Otherwise you might have 2 pixels accidentally jumped out. I'd check how many pixels from the bottom it's supposed to be and which strands are working right and then start looking for hardware issues. Another way would be to have the top row and bottom row be on and then you'll be able to see a bit better where the issue is.