Conlan - I've made some tweaks to the rendering which should prevent the "double Ok button" in the popup.
The other issue is simply query speed. If you wait on the page before pushing "next" do you ever get the quiz section loaded? If that happens, all the subsequent functionality should work. We were expecting you to read for a while before getting to the bottom and so were querying our records in that order... You just are too fast for the current architecture.
As you can imagine this application is testing some of our Spark release features. Initial work has proven too slow - and we are doing some rearchitecting. That improvement has yet to be applied to the Learning Center application. Its the problem with dogfood..