Star Wars Episode 4: A New Hope - Now Where Is the Dimple in the Death Star Again?
During the briefing to the Rebels prior to launching the Rebel attack fleet, and in other scenes, the Death Star is computer-projected in wireframe. In every projection the main weapon Dimple is located on the Equator of the Death Star. However, the actual Death Star has it's main weapon Dimple to the North of the Equator.
This means that R2-D2's great and important 'plans' which were analyzed to reveal the design flaw of the Death Star are pretty tragic.