All of my students submissions show as past due despite there being a due date and a grade entered. I have tried "mark all as complete" and it does nothing. Similarly I have a list of "new submissions" in my assignment list saying there are 57 new submissions (for an assignment due the second week of class in which all grades have been entered) and no matter how many times I select "mark all as complete" they continue to show up as 57 new submissions. Help!