         syncColumnCellResize: true
         rowHeight: 35
         headerHeight: 38
-        numberOfColumnsToFreeze: @listVisibleCustomColumns().length + 1
+        numberOfColumnsToFreeze: @gradebookGrid.columns.frozen.length
       }, @options)
 
       @setVisibleGridColumns()

      @studentViewStudents = {}
      @courseContent.students = new StudentDatastore(@students, @studentViewStudents)

      @allAssignmentColumns = []

      @gradebookGrid = {
        columns: {
          definitions: {}


      for id, assignment of @assignments
        assignmentColumn = @buildAssignmentColumn(assignment)
        @gradebookGrid.columns.definitions[assignmentColumn.id] = assignmentColumn

      for id, assignmentGroup of @assignmentGroups
