Black renderer nvidia gt 745m

Hello,

I’m running windows 8.1, I have an NVidia geforce gt 745m and the internal intel HD Graphics 4600.

I have found that vvvv runs with the intel card but not the nvidia.

dx9 renderer windows are black and stay that way.
I have the latest drivers. Crack .exe seems gives me all green lights.

Any thoughts on what I could do to get this working?
Or is my card incompatible for some reason?

Thanks!
Pete

Hi
Maybe the optimus problem ?

forum-alpha/optimus-and-v4-behaving-differently-on-different-os-versions-%28win-7-win-8.1%29

Thanks, despite searching I didn’t find that one.