Changes made to grades in FA Web will not change grades that have been previously posted to Registrar's Office. To change the posted grade, grades must be re-posted and the box must be marked to update existing entries.
Grades can be posted from Administration, Post from FAWeb. On the General tab there is an option to "Update existing entries". When this option is marked, the newly posted grades will overwrite existing grades. If this option is not checked then the original values will not be overwritten. If grades need to be updated for some students in a class, but not others, the grades must be edited manually in the grades Module.