I don't know if it's a bug so I post here. If it's a bug I'll file it on Mantis.
Tested on 0.9.4 and 0.9.5 svn
Ubuntu 12.04 64 bit with Sunab repositories (tried with 0.9.4 from release and 0.9.5 from svn)
When I overlap something (e.g a title) Kdenlive doesn't select any more Composite as automatic transition. Instead of it, it selects Affine transition. Which is a great thing because it combines together "Pan & zoom", "Crop & Scale" and Composite, and more.
But it looks like it has a problem: when I render it on not very contrasted clips (e.g. a misty morning) when the title starts I can clearly see the picture increasing its level of contrast, coming back to its normal levels of contrast when the title goes off.
If I use Composite instead of Affine, this unwanted effect disappears.
Is it something I don't use properly or it's a bug? Do you have the same behaviour on your PC? Is there a way to tell Kdenlive to apply automatically Composite instead of Affine in overlapping titles?

Sure. Actually I can clearly see now that the effect is more present on clips showing grass or plants. So it's surely the same bug. Thank you very much.