SmartRendering - only during preview

[thinkstorm]

Hi all,
after following the discussion about Gin and Oranges, i am still confused about SmartRendering (and VS9):

When placing two .AVI from my crappy digital camera onto the timeline and want to preview the clips (by putting the marker somewhere in there and pressing the play buttton), VS9 starts rendering the whole project, so both files. Ok, understood, it has to generate the preview, great.

Now, when I place a transition between these two clips, I would expect that only the transition gets rendered. Unfortunately, everything gets rendered again.

Did I miss the right setting somewhere?

Cheers, Thorsten