It is almost certainly the same issue between HT and dual core. I first saw this when I tried to run on an XP machine with HT enabled a few years ago. The only way it would run was to disable HT. With DC, I must set the affinity of both the app and mappoint to the same CPU (or of course disable DC).

I have been hoping eventually a MP update would be able to run in such an environment (let alone take advantage of additional resources), but so far that is not the case. Maybe the silence on the next MP release means MS is working feverishly to address this... or more likely, they havent decided whether to ever release another version...