MIRO function area error

hi guys,

When i use MIRO,function area(FKBER) is not re-derived after new cost center.

I create the badi 'BADI_FAREA_DRV_ALWYS' and use method 'SET_FAREA_DRV_ALWAYS' set C_FAREA_DRV_ALWAYS = 'X'.

It works!

Now,I don't want it work.

I delete the method,MIRO is not work.

But the accounting document is also work.

(EX:cost center 11111 : function arer = YB30；i change function area to YB20,and post it.

The accounting document's function area is YB30,not YB20.

How can i fix it?Thanks.