Thank you for your reply Gareth. I noticed that the student was doing a little fiddling with the submission. I believe he may have been leaving the submission popup window open but then clicking the submit button after the deadline time. I wonder if that could cause the 0 time entry error. This error has ocurred for only two students out of a class of 589, so I'm leaning to the idea that it may have something to do with how they did their submissions.