Change Quantity in Part List

Hi,
I would like to know if anybody can share their experience about chaning the Quantity in Sale Order / Work Order / Part List
When my user change Sale Order Quantity the related Work Order Quantity got changed. But the Part List Quantity did not get change.
Is anybody know is this a bug in the system or the setup issue or the system as design as no update to Part List when change Sales Order ?
Thanks in advance to share your expertise and experience
Application 8.12 Tools 8.97.23 SQL 2005

We're on E1 9.0, but I think this is a setup issue that is the same between 9.0 and 8.12. The version of P4210 you are using should have a processing option to specify a version of WO Entry (P48013) to use. Check the processing options of that version of P48013, and look at the value for the Validating.Quantities and Dates. If set to 1, the program should recalculate parts list quantities and routings if the WO header quantity or date changes; if set to blank, no recalculation will take place.

Hi Don:
Thanks for your reply. Yes we do have processing option set to 1 for Quantities and Dates under Validating. Please let me know if you have any other suggestion. Thanks sl922