With your code I have all four in the cursor.
Check picture.


>*Cursor with unique list of string
>CREATE CURSOR c_UniqueString (cStr C(50))
>
>*Cursor where we want to find all unique string from.
>CREATE CURSOR c_Data (cCode C(40), cdesc C(50))
>
>INSERT INTO c_data (ccode, cDesc) VALUES ("ARIA", "Ariane")
>INSERT INTO c_data (ccode, cDesc) VALUES ("GALA", "Gala")
>
>SET EXACT ON
>SET ANSI ON
>
>*First column
>SELECT DISTINCT CAST(RTRIM(cCode) AS V(40)) as string FROM c_data WHERE !ISNULL(cCode) INTO CURSOR c_DistinctCode
>
>INSERT INTO c_UniqueString (cStr) SELECT string FROM c_DistinctCode WHERE string NOT IN (SELECT cStr FROM c_UniqueString)
>
>*Second column
>SELECT DISTINCT CAST(RTRIM(cdesc) AS V(40)) as string FROM c_data WHERE !ISNULL(cdesc) INTO CURSOR c_DistinctDesc
>
>INSERT INTO c_UniqueString (cStr) SELECT string FROM c_DistinctDesc WHERE string NOT IN (SELECT cStr FROM c_UniqueString)
>
>*We should have 4 values in c_UniqueString, but we are missing Gala in lower case. The NOT IN does not take into account Lowercase and UpperCase.
>
>Any work around ?