Connection Problem to DB Table

I have an existing postgres DB that is functional. I am trying to make
changes to the DB, and I am creating a new test db to play with before
moving it over. I am encountering a problem when attempting to execute a
SELECT via a php web interface:

Warning: PostgreSQL query failed: ERROR: lookup3: Permission denied. in
/var/www/html/harbornet/admin/lookup_street2.php on line 52
An error occured.

The line referenced is:

$result = pg_exec($connect, "SELECT * FROM $tablename WHERE house LIKE
'%$newaddress%'");

which refers to:

$connect = pg_connect("dbname=harbornetdb user=harbornet password=HN_pgsql");

I know that I have permissions set incorrectly for the table, but I cannot
figure out where my mistake is. The table name is lookup3. The exact same
PHP code works for a different table in the same DB by the name of lookup2.
I tried the following GRANT statement to no avail:

GRANT all ON lookup3 TO <username>

Any help is much appreciated. Thanks.

Jeff Hunnicutt