Student Report with Letter Grades

Two part question:

1) Can I use numbers instead of letters for the grades? We use standards based grading, so 1, 2,3, 4. It seems to work OK in the settings.

2) When I generate a student report and ask it to show both (percent and letter) the report only shows the same Letter (in this case a 1) for every student. On the actual gradebook tab, it is working correctly where students have either a 1, 2, 3 or 4. So the gradebook is working, just not the report.