problem with SELECT DISTINCT against an empty column

i am running version 7.1.3-2 (downloaded using GNORPM) on Linux 7.2. i have
created a database, and populated the database with some rows, using a
command like:

INSERT INTO database VALUES ('','19','red');

i inserted 20 records, with different values for the second and third
column, but leaving the  first column blank each time.

when i do this command:

SELECT DISTINCT Colunm FROM database ;

i get back one record, which is empty (when i print it out like this:
printf("****%s****",entry) i get ******** out.)

it looks like the "right" thing is happening, in that there is no data, or
is the lack of data considered data, if you understand what i mean?

anyway, how can i reload this database with these entries actually empty,
so that "SELECT DISTINCT" returns "PGRES_COMMAND_OK" rather than
"PGRES_TUPLES_OK"?

thanx alot. i appreciate the work you have done so far. i am sure i am
making some mistake here, but i have been all over the web site, and
haven't gotten anywhere.

i appreciate any advice you can offer.

stev knowles