Windows is pretty stupid in assigning CPUs I have found. If you fire up 1 client, you will see that none of the CPUs is using 100% that is because Vista is bouncing it around from CPU to CPU even though there is no load on the others. In Windows if you are running any DC stuff, it is a good idea if you can set the affinity so things stay put.
I was just asking IronBits about his affinity numbers because they seemed strange to me so I was thinking maybe he used that to avoid setting them to a hyper-threaded "core".
Jeff.