I have a bug that's just popped up in the last week.  It's happened twice so far.  I'll load a saved figure and the eyebrows, eyelashes, and hair are solid.  When I go into the material room, I see that the transparency map has been replaced with the current  texture map.  If I try to reload the transparency map, whether from the list or by browsing, the current texture map appears again instead of the transparency map.
I also noticed that in the "advanced" section of the material room, the node connected to transparency has the correct name of the transparency map, but with the picture of the texture map.
Now if I turn the transparency map strength all the way down to 0 and then all the way up to 100, the tranparency map magically appears in its proper place.  However, although it's in its proper place, it doesn't have any effect.  It will do its job if I delete the texture map, but as soon as I load any texture map, the new texture replaces the transparency map, and I'm right back where I started.