Just read the Release Notes for GVI and was quite shocked.
Especially about 2 things which are not supported.
1.) 64 bit Cpu's
2.) Dualcore/Multiprocessor-> if you want to run multiple instances in Cubase/Nuendo.
You have to uncheck the little box "Multiprocessing" in Cubase/Nuendo.
What a bummer. I'll wait till this is sorted out.