I just download the Blender 2.66. The first thing I did was to render a image from a .blend file created in the 2.65a.
The first one was rendered with 2.65a and take 2min43sec, and the second with 2.66 take 6min48sec.
The only thing I noted is ,with the 2.66 when I open the .blend, the terminal show :
“read blend: /media/Blender/3D PROJECTS/Borgia203/Models/Set.blend
2.66 versioning fix: replacing black sky with premultiplied alpha for scene Scene”
It seems to be just an information, not a problem warning.
Any clue why this difference in render time?