Hi there,
After upgrading to CS6, i'm facing some pretty severe problems with rendering.
My edit machine - my windows machine - plays the clips fine, but in the moment I watch the clips on my MacBook, iPad, Vimeo, Youtube some really nasty artifacts starts to show.
I just made a clean install of Windows 7 with all the latest drivers.
The system is:
Windows 7
Geforce GTX 570
12 GB ram
Intel i7 4,1ghz
I use Magic Bullet Looks for grading.
I guess that is what's relevant!? 
I'm really absolutely clueless about what is causing this. I tried to render with Media Encoder, as well as the Premiere. Same result.
Attached is a screendump from Vimeo that shows the problem.
