I'm not seeing anything labeled preview. The thing is, if I hold the mouse over the window, I can switch back and forth between outlook and any other window EXCEPT fancast. I don't know if this makes any difference, but the window with Fancast was actively playing a video.
I can tell by looking at the icon in the quick launch area that there is more than one IE window open. When I move the mouse over to the IE icon, the preview windows expand. The window with the Fancast video won't stay open.