You could try erasing the stripe where the door is, and redraw that section of the door stripe alittle higher or lower whatever the case may be with your door, and see if that works. Alot of the times we are at mercy of the model maker and do the best we can. Especially when painting shared .dds files.

Study your texture file closely and see all the parts, and identify each part of the aircraft. Your problem is a common one we all face at one time or another. It can be frustrating if we let it. That's what we get for trying to be a perfectionist. In time you will know how to paint a specific texture file, and what will work best on what aircraft. 

The more we learn filters and the tools offered with our Paint Editor, the more we learn to manipulate just what we have painted as well.

Painting in layers is a very good way to learn to paint aircraft, we now have the abilty to edit (add/remove/recolor) just the white of the aircraft on one layer we painted, or just the stripe we drew on a different layer (add/remove/recolor). Sometimes this makes it easier to make the adjustments needed to just a specific area.

Good luck with your paint.

Added Note:
After viewing the file in question, I noticed where the door was, the line they painted across the door in Texture.1 folder was erased from the gray seal around the door, possibly to help break the line up and not make it as noticable offset.