Warehouse Request not updating

Hi,

I have a problem with correcting shipments and I hope that someone can guide me with this. I'm using warehouse shipments and I need to correct already posted shipment quantity. As I know then I cannot change already posted warehouse shipment partly. I did the following:
1) Deleted posted warehouse shipment
2) Undid needed sales shipment lines
Then I wanted to recreate new warehouse shipment but I cannot cause it's saying that nothing to create. I know that this function is checking warehouse request table but this table has on this record field "Completely Handled" filled. I hoped that with undoing sales shipment lines program automatically refreshes this table as well but unfortunately not

Am I doing something wrong or this is a standard functionality and I have to refresh sales order lines as well to get warehouse request updated.

Thanks in advance,
Anti