I have an (ungraded) class that I require students to upload a file showing their work on an exam. Once the due date has passed, I go look at the exams and I use "pins" to leave feedback. Then I mark the exam as "incomplete" i Speed grader so that I know I've looked at it once (and I can see in Grades if there are any that I have missed).

A week later, I make a second pass and respond to students' answers to my feedback and mark the exam as "Complete".

At the moment, only about 2/3 of the grades for the most recent exam are showing as Incomplete in Grades. The others show that the submission needs to be  graded. But I've graded them. I've changed the grade in Grades from "ungraded" to "Incomplete", but the Incomplete grade doesn't "stick". 

I've tried changing it directly from Grades as well. When I see a "submission" icon and hover over it, it changes to the Incomplete "X". Then, whether I actually select the "X" from the pulldown or not, when I click away, it reverts to the submission icon. Students are seeing this as well, so even students whose exams have been reviewed are seeing the "ungraded" status.

UPDATE: I just noticed that in the Speedgrader, some students' grades are showing as Incomplete even though they are still showing as ungraded in Grades.