Hey Philco,
this may be related or not but in DP i get CPU spikes when i have a Kontakt instance opened. Even if they are both idle. VEPRO is not even opened.
Try experimenting with Kontakt's multi-processor preferences. I know that NI advises against enabling multi-processor support in K4 as they say that the DAW should take charge of this. As for using K4 within VEPRO i don't know what would be recommendable?
HTH
Best,