Different brighter Render Result after Software Update

Hello my dear Blenderinos!

So i have run into a very annoying problem after i updated to the newest Blender Version 2.71.

Before the update i had a 250 frame animation cycles gpu render going up to 215 but had to interrupt the render myself. I remember back then that the tile size seemed oddly small although i had size 256 and were definitely set on GPU rendering, anywho i found that the results were very pleasing (before photo). Then I installed the update and reloaded the project to render out the last remaining frames. This time the tiles were appropriately bigger like you are used to with a tilesize of 256 but the results were weird. the background seemed to stay exactly the same but my model seemed all brighter and with less contrast which just looks ugly (after photo). maybe this is a known glitch and somebody can point me into the correct direction? Again, I havent changed any render settings.

Due to copyright reasons i can only show a small part of the image but you will get the idea i guess.

Before:


After:


Any ideas?

What version of Blender did you upgrade from?
First thing that comes to my mind is that the clamping setting has been split up into clamp direct and clamp indirect from version 2.70 (I think) onwards. So, if your scene has been generated with e. g. 2.69 and has clamping enabled, it will open in 2.71 with clamping disabled because of the now split settings.

If everything else fails, you could just get the zipped version of your former Blender and finish your animation render with that?