@Duke461 That's odd, it works on safari for me and I've been developing in chrome. There is an error console that can be opened from the Develop menu (which in turn can be enabled in (Prefences / Advanced / Show Develop menu in menu bar). If there's an error post it and I'll see what I can do. Otherwise, if you're happy with firefox stick with it.
@everybody I'm playing around with another interface for dragging the ubertubes. It will limit you to three ubertubes. I'm just checking that there are no bugs, feel free to try it and let me know what you think.
http://norwellrobotics.com/calculator/alt/