Pb with NagaRoyalGuard skin

Usually when I edit a skin I don't get too many problems (model unable to load the skin correctly). Sometimes alpha layers create problems, and they seem to be easier to handle for certain models than for others. But I've tried to edit the Naga Royal Guard's skin and often the model was able to load the skin there was no pb with green box), but it was just all black, except for team color. I had already had that kind of problem, except that the rest of the model was not black but invisible, but this time all I could find out is that if I import the skin as the last imported file in a map I don't get the problem, but if I import another file after importing the skin then it doesn't work anymore (and the size of the imported skin goes up from 196 to 200). Is there some rationnal explanation to this problem?