Material with transparency working in pview but not in game

Or more simply, load into PView a model that has material transparency but not texture-transparency. (The egg-file linked earlier in the thread will do, I believe, but I had the same result with a quickly-made model of my own.) Once PView starts up, press the following keys in the given order:

C
This should centre the model, of course.

L
This should activate lighting. If this behaves as it does on my machine, note that the model’s material-transparency is used as expected.

P
This should activate per-pixel-lighting, that is, shader-based rendering. If this behaves as it does on my machine, note now that the model’s material-transparency is no longer used–the model becomes opaque!

The problem is. set_shader_auto() expects a texture for transparency. Although this looks like an error.