Steps to reproduce:

• Go to the Grader Report for any course.
  (this happens regardless of whether or not "grade_report_fixedstudents" is turned on)

Expected results:

• The averages should line up correctly with the corresponding students
  (see graderreport_expected.jpg attached)

Actual results:

• An extra table cell in before of the averages but after the "Overall averages" heading
• This element is being inserted: <th class="header userreport"></th>
  (see graderreport_actual.jpg attached)

I've managed to track this down to around line 1176 of "/grade/report/grader/lib.php" which looks like this:

if (has_capability('gradereport/'.$CFG->grade_profilereport.':view', $this->context)) {
$avghtml .= '<th class="header userreport"></th>';
}

I've confirmed that this is code that's causing the problem, because when I comment it out, the extra table cell disappears.

I've confirmed this on three different sites using the following Moodle versions:
Moodle 1.9.7+ (Build: 20091231)
Moodle 1.9.7+ (Build: 20100106)
Moodle 1.9.7+ (Build: 20100121)