Customer address save error 'Value XXX for the flexfield segment State does not exist in the value s

Hi,

Customer address  save error 'Value XXX for the flexfield segment State does not exist in the value set XXX ',but the state value is in the list of value set of the segment,we can  choose the value in the customer OAF Page,but after click 'save' ,then raise error,Why?

we personalize the page ,add a flex column of country,then state segment value set  can changed when country changed. use $PROFILES$.Country

Thanks.