Very stange bug with billboards

[lantis]

Look at normal scrrenshot:


And its happen if im try make trnasparent texture in .x file with tree
for(int i=0;i<Model1->getMaterialCount();i++)
{
driver->makeColorKeyTexture(Model1->getMaterial(i).Texture1,video::SColor(0,0,0,0));
Model1->getMaterial(i).MaterialType = irr::video::EMT_TRANSPARENT_ALPHA_CHANNEL;
Model1->getMaterial(i).EmissiveColor.set(255,255,255,100);
}


Billboard texture with player name stand behind tree! ;(( any ideas?