Engage and Quizmaker Doesn't Close After Save (Windows 8)

Hi,

     My version of Studio ('13) is behaving strangely.  After opening, designing and saving a piece of Engage or Quizmaker Content, the program stays open on my taskbar until I end the task through Task Manager.

Does anyone know how I can stop this from happening, as it's mildly annoying!!

Thanks in advance....