I have Safari on my first space, And photoshop on the second. When I switch to the space where Safari is and then switch back to PS, sometimes, PS just hangs and I can't select any document window or type anything. I have to switch a couple of more times back and forth to get it to work. This usually happens when I'm trying to add Layer styles. I can't change values often for some reason when I switch a space. Just as a side note, I have all of my spaces filled and I use 3x2 spaces. I don't think thats the problem though because I have tried with inly 2 spaces filled and I still encounter problems.