Default value box won't uncheck

Default value box won't uncheck

I have created a custom Pick List field for the Client module and it I have unchecked the "Use first value as default value" box and clicked Save. However, whenever I go back in to edit that same field again, the box is checked, and when I add a new client, that field is defaulting to the second value! EEEEEK! Help? (It's the field I've entitled "AmLaw" for Clients)