1. When you click the new button to select a region, the cursor changes to cross-hair and you should now be able to click and select a region on the screen; after you do so it will fill in the values of the region you have selected into the options dialog in front of you indicating the region location and size. It works here. Anyone else?
2. It refers to the active window at the time of capture.. in other words it tracks whatever monitor your cursor/mouse is currently in.
I could add an option that let you specify a specific monitor # for capture, but I'd like to get the region select to work first; it seems to be working here.