INVSDOIO -Define Inventory Organization Parameters not saved,the default cost group not change

Hi Experts

      Use the EBS inventory module  define inventory organization paramater, Before save the set up ,the default cost group not change;

      Already  set up the  two cost group  for multiple organizations;

   Questions:

1.Why not change the default cost group,

2.  what setup effect  generate the default cost group ;

thanks  in advance!!