I have the same problem here with a Mac installation...
The last VEPro update made it a litle better but what seems to happen here is the CPU usage in VE Pro witch drops sundenly to 0% and that cut the sound ! then it comes back and forth...
Very anoiying as my system worked fine untill a couples a weeks ago and I've been triying everithing I know to solve this (network installation, set up in Kontakt and VEPro etc...) but nothing worked so far...
Maybe another update is on it's way ? if so let us know when it will be available and if you can replicate this strange behavior...
My setup : Mac Pro Nehalem 2x2,26 Ghz Quad core Intel Xeon with 32 Go Ram, SSD drive for system and several HD on external FW 800 this is the Master DAW runing Nuendo 6.0.7 then i have and I-Mac 3,2 Ghz Intel Core I5 with 32 Go Ram with external HD for libraries. Both are running OSX 10.8.5 and are connected by Ethernet to a hub with cat 6 cables (all new)
Regards