Flippi, I removed "colorPaletteMap[2] = "vehicles/fullsize/HNLpopo/HNLpopo.dds"; and the skin works fine. You're issue lies there. FYI - I downloaded the HNLpopoold.zip. You likely have a similar problem in the other one.
It's only for skins that would use multiple color channels and it requires a special skin file for it. The diffuse/overlay map would be the same pretty much.
