Hmmm...

I could be mistaking, but if the graphs in the task bar are filling up, even if not at a high percentage, does that not mean they are being utilized?

I will admit, with Poser Pro (just double checked) my CPU usage is sitting at about 50% (where as a render with Carrara goes to 100% on all processors), but for the most part, it appears to still be spreading the workload out to all 8.