         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: {}

      pattern = new RegExp(@userFilterTerm, 'i')
      _.any propertiesToMatch, (prop) ->
        student[prop]?.match pattern

    filterAssignments: (assignments) =>
      assignmentFilters = [
