Dynamics GP Class Behavior...

“Dynamics GP Class Behavior”…. The day when I started working in Dynamics GP I was impress with the “Class” and its “Roll Down” feature just do the simple changes and it will update all Master Record. Unfortunately all these days I was thinking “Roll Down” features will “Roll Down” all the information from “Class” to the Master Data .
Here the issue I face - Imported the Customer Master using eConnect using default Existing “Class”. After importing found that I have to make two changes in Customer Master one in “assigning GL Account” and another is in “Payment Terms”, it’s so easy just update the Class of the customer and it will reflect all changes in all respective customers. Instead of making both changes and saving I mistakenly did first change Assigned the GL A/c and saved without “Roll Down” did the second change in “Payment Terms” and on save, clicked on “Yes” for “Roll Down” expecting system will pick GL A/c which recently assigned and all other Information from “Class” and do the update in Master Data.
But when I checked my customer Master for those “Class” my GL A/c field didn’t get updated. Only the changed happened to the “Payment Terms” field.
It was my assumption that once I made the changes to the one field in “Class” and on “Roll Down” it will update all respective field in Master Record but it won’t it will do the “Roll Down” only for the “Changed” field.
Again only the field you change it will Roll Down in Master Data not all fields