Images As Planes: Strange transparency issue

I am experiencing a strange issue with regards to the transparency of PNGs used on a 2d Plane. Each of the planes are imported using the Import Images As Planes plugin (Shadeless, Use Alpha, Alpha Mode: Premultiplied, Z-Transparency, Dots/BU @ Definition=300, everything else off).

Looking at the image below, the 3d viewport background color/grid shows around each planes.

But, after selecting the 2d planes or switching from solid/textured to rendered, it goes away.

I’ve tried changing “Clip Alpha” slider in the System User Preferences, premultiplied/straight, switching Blender Game render engine and changing Alpha Blend to Alpha Clip under Game Settings.

I created each of the PNGs from photoshop. Anyone have an idea of why the 3d viewport background/grid is showing through the overlapped image planes below?

I don’t see any error. That is the way Blender and most other 3D packages present alpha based images to the end-user. My guess is pre-multiplication of alpha only occurs when you render. This way the viewport remains responsive. If you want an unresponsive viewport simply leave it in Render mode all the time.

Viewport only shows 1bit alpha when not an active selection. Not a bug just a layer limitation.