Predefined Values; sys_pre_values

There is a bug somewhere. I am trying to locate it.

I am posting in the General section because this may be a misunderstanding on my part.  On a site I managed, the Ads module is installed.  The owner wanted "United States" as the first in the drop-down list for Country.  In the Predefined Values section under "Builders" I go to Country and I move "United States" to the top of the list.  However, when I go to the Ads section and create a new Advert, Afghanistan is still at the top of the list.   Going to the sys_pre_values table I see that "United States" does have a position of zero (0).  So, am I confused on what the position in the Predefined Values does?