Territoty employee Partner function cannot be changed

Hi Gurus

I am trying to change the attribute partner function of bol object "TerrEmp" via Bol Browser....no sooner did i change the value and clicked on save it was getting reverted to an old value with system giving the message" entity saved successfully".

Path: TerrSearch-->TerrHeader-->TerrSPO->TerrEmp .

attribute to be changed  " PARTNER_FUNCTION"

Regards

Sanguine