After much frustration and pissing in the wind, I finally found the solution. I had to manually assign each client a core. To do this (Most of you probably know, but since i didn't see it in here anywhere....)

Open task manager, go to processes > right click xxgame.exe > right click Set Affinity > check the box for the core you want to run that client, rinse and repeat until each client has its own core.

Thanks for the help nonetheless, found out lots of nice other tidbits while cruising these forums looking for a solution!

Sohber