Bain,

After the import, select all of the K1USN QSO records from the Recent Contacts main list, Click Edit from the top menu bar, click Fill Fields Determined by Call, click Selected Records.  That will populate missing fields such as state.  

You have to have a CallBook lookup source like QRZ, free AC Log Calldata, etc. for this to work.

73, Mitch
NWØM