Doors in AC are scripted in a way which allows one and the same material to have different mapping coordinates and appearance. In your case, this makes the wood grain rotate horizontally in the upper casing. This is a great feature, which AC users take for granted! But if you model a door in another application or export an AC door to a rendering application, you will have to remap manually each wooden piece to achieve the proper appearance.
About 90% of doors with veneer finish have vertical orientation of the veneer grain. For example - doors in my office! 😉 So, the person who wrote the door object assumed it as the default option.
