You are right chocomog. I thought I had fixed it, but I didin't. Oh well, I'll do it for the next release.
There are also 2 more bugs that I must solve:
-Adding polygons on a multi-group p-file (any textured file) will cause the file corruption. I've solved this problem already so the new version will be fine.
-The vertices order on poligons is wrong sometimes. That's a bad thing because the game thinks that they are facing inside the screen (and thus, won't draw them). I don't really understand how must the vertices be sorted, but I think I can solve it easily.
Sorry for the lack of updates, but I'm "bussy" testing my ViperGC