--- Operating System, Graphics card ---

Win 7, 64 Bit. Nvidia 460GT

--- Blender version with error, and version that worked ---

r54785, Blender 2.66, Version that works: Blender 2.61, r43268

--- Short description of error ---

Blender internal renderer doesn`t render images with transparent background anymore.

--- Steps for others to reproduce the error (preferably based on attached .blend file) ---

Render the content of the attached scene.

I wanted to render a picture with transparent background, like i did quite a few times before. So i switched the standard output png settings to rgba as usual. And to my surprise the result was opaque. The transparency didn´t show. The resulting image is 32 bit as it should. But the background colour is not set to transparent. I have then digged in my old Blender backups to find a version where it works fine. And needed to go back to 2.61 to do so. The with 2.66 written scene had quite a few problems with older builds.

As a sidenote, while building the attached testcase i have somehow managed that the book doesn`t show its texture in the workspace anymore. I had to change the texture paths manually after moving the blend file to another folder. (God, how i wish that Blender would use relative paths relative to the file instead those insane absolute file paths that nearly never ever fits when you reload the scene ...) The rendering is fine though, the texture gets rendered.That may be another bug.