Fuselage textures not aligning 737800 paintkit

I've noticed that other posts make mention of the gap or join marks in the aircraft fuselage after repainting. I have a similar problem , in that, I can't get the alignment between fuse 2 and fuse 3 to align correctly. I paint within the guidelines of the paintkit, have repainted many times, but still have the problem. I know the fuselage is aligning properly because the windows are straight and in their correct position, when viewed in FSX, but not the paint. Help, anyone?