Why is it recommended to unbind bussiness object before save operation?

I have WinForms application.

Some save operations may take few seconds. Usually, while saving is in progress, I'm blocking (Enable = false) main Panel control which contain all binded controls (TextBox, Combobox etc.) and unblock it when save is done. I don't unbind datasource, so I see my values on controls. And that's what I like.

But when we set DataSource to null (before save) - all my controls are empty until save operation complete. That is what I don't like.



So why it's suggested to unbind?