bleeding textures?!!

[churruca]

I am working on a 737_600. My problem is that at dusk I can see through my model and at night the night textures dont show at all.

Does it have something to do with the alpha channel? What shall I do?

What format should the different textures be saved in?

what program is best to make the textures. Photoshop or paintshop and why?

Your help is much appreciated. I tried all kind of combinations with the alpha channels in the _L texture. Have not changed the alpha in the _T texture, because it has the right reflection at daytime.

thanks in advance.

Jacob