I have found that even though the info for the hotspot says adding an additional point is not possible that there is a way to do so. If your hotspot has 5 points and you would like to make it 6 in order to chagne the shape or something, just copy one of the existing control pont cooridantes and paste it right below the line that was copied it will stack the points on top of each other, you can then go into the editor and move the new point to where you would like it. Has worked for me a few times.
http://www.virtualnorthland.com/ (work in progress)
