Raise do_not_save is not stopping document from getting saved

Hi,

I have created a implementation in order_save badi, where on certain condition i am throwing a error message and raising exception do_not_save but the document is getting saved. why is this happening  and how do i over come this.

Note: few of the implementation in order_save badi have used BOL programming and i am not sure but have heard that BOL programming in ORDER_SAVE badi can cause "Raise do_not_save" not to work. Please suggest.