Some video card drivers for dualview mode allow you to specify that certain applications get sent to certain displays. You might check and see if yours allows that.
It is amazing how much productivity increase there is with two monitors. I would never have believed it was as much as it was until I did it.
At work I used to have two 19" LCD's. At some point I was lucky and acquired a 30" Dell widescreen with the idea that it was equivalent to the two smaller displays. It wasn't.
So now I have a 30" and a 19"!
