When sorting the assignments by grades or comments those students that have submitted assignments will be sorted differently to those who have submitted no assignment when the grade or comment field is empty.

For example when you sort by grade in descending order you may get:

• No Grade
• 97
• No Grade
  as the order. This is caused when one of these No Grade results is from a student who has submitted an assignment that has not been graded and the other from a student who has not submitted an assignment at all.