Gradebook

This thread: http://moodle.org/mod/forum/discuss.php?d=147442#p650379 was started in the Assignment module forum, but should probably be here instead.

To recap:

Our professors can use the Grader Report with Quick Grading globally enabled to enter grades for some number of students. However, at some point, the grades are no longer saved.

For instance:

A teacher has a course with several sections of students, broken into groups. They enter grades a group at a time. One group has 21 students.

Using the Gradebook, View tab, Grader Report, they are able to enter grades for these students, then click update, but only the grades on the first x-number of lines are saved. ("x" appears to be a declining number - was 14, now has degraded to 13...)

Subsequently, while grades for the students appearing in the 15th - 21st lines lines can be edited in the Grader Report, they will not be saved when the page is Updated.

If the students' grades are edited individually in the "Edit grade" screen, then saved, they will appear in the Grader Report as entered.

If the student names are sorted differently (i.e, first name vs. last name) it is again the first x-number of lines (14 in this example) appearing on the form that will save the grades entered.

So far, we've found no way to fix this screen. The only way to reliably enter student grades and save them (after the first 14 lines or so!) is to edit them individually.

We're continuing to experiment to try to find a reason why. Just to complicate matters, this behavior is not universal to all courses, so we're struggling to isolate the activity, setting, whatever it is that seems to be causing the problem.

Any help?