Snap snap snap

This blasted jigsaw puzzle is driving me nuts. The bottom edge pieces together perfectly as does the top edge. All pieces snap nicely together and the pictures work excellently except for the fact that the bottom edge is about 6 pieces longer than the top edge. I can't quit working on it until the anomaly is resolved! It's like some wicked puzzle maker through in a few extra pieces that just so happen to line up correctly simply to drive me nuts!