How does isboxer handle switching windows if when different cards are running? Or does isboxer just act as a go-between for the user and the OS? What i mean is, are there settings you have to fiddle with in isboxer/innerspace or is it all handled behind the scenes without any user interaction required?

Because if you have the main window on card one and the four slaves on card two, whenyou switch from toon a to toon b showing up on the main monitor, then at that point card one is handling toon b and card two is handling toons a,c,d,e. This would have to be the case since card two is not connected to monitor one and card one is not connected to monitor two.

Is this even possible without an SLI setup?