I've followed the instructions correctly (I think), but can only get the hair partially working inside New Vegas (see screenshot here: http://i55.tinypic.com/11793mc.jpg ).
The problem seems to be with the Hat mesh. Without a hat, the hair is displayed fine, but wearing a hat either does not display the Hat mesh at all, or displays the NoHat mesh. I've checked each individual property between my hair mesh and a vanilla hair mesh and cannot seem to find any differences.
Can anyone help? What am I doing wrong?