everything acting weird usually doesnt have an attached texture.
have you lightmapped the addons?
by lightmap i mean to make a new wrap for the untextured object?
its hard to explain. but a few people around here know, and this is the wrong part of the forum to post in, you would have better luck in the Fleet boat mods workshop, where all the brains hang out...this is where you complain about how ur D2D download isnt working
also, make sure your textures are rotated properly, that will cause a little bit of irregularity
hope i helped!