just in case someone elses run into this problem, i leave this statement here.
ati seems the more sensible choice in dx11 development nowadays, but today I ran into an issue with it. I tried to run a patch that had been running with former vvvv installations with ease. But today it crashed the entire vvvv hard, and it was amazingly hard to find the cause. Even with proper debugging settings totally unrelated nodes reported issues, and in the end it was a program called plays.tv
It is something that installed itself along with ATI drivers, and allows to film game renderers in real time, much like twitch, obs or fraps. When it automatically hooked into a dx11 renderer window, it failed the whole renderer, and in the process vvvv completely.
Uninstalling plays.tv fixed the issue.