Yes, that is where it freezes. Where did you read that information? The thing that baffles me is that I could run dual monitor mode and play 1 instance on one screen with my 7800 GT and it never, ever froze. The frame rate was brutal unless I turned everything way down in game, but it still...
I just upgraded my video card from a 7800GT to the eVGA 8800 GTS and I can not run City of Heroes (only 1 instance) when I am in dual display mode. I was able to run it on my 7800 GT (even with a DVD playing on the other screen), but with a crappy frame rate, hence the upgrade.
My system...