Well, the difference is that I now use Kontakt 6.2.
I have one PLAY instance, and a few Spitfire Labs instances. They used to get a long with each other. I know, there can be a million reasons.
I'll try sending a crash report next time.
Also, what is interesting. When idling VEPro says whatever e.g. 7% CPU load - someting that seems right - however, the activity monitor says more than 100% percent load. That is certainly strange.