Steps to reproduce:

1. Create a quiz with overall feedback <7 below 70% >7 above 70%, grades displayed to 0 decimal places.
2. Add one essay question to the quiz, worth 1 mark, quiz graded out of 10.
3. Attempt the quiz as a student.
4. As a teacher, manually grade the question as 0.69 / 1.
5. Check the quiz reports. Student 1 7 feedback <7, overall average 7, >7.

Something has gone wrong with the feedback for the average, and the cause is that the grade was rounded before being stored in the quiz_grades table.

This bug does not occur in Moodle 2.0.x.