Inserting an empty string inserts a space

I'm having difficulties inserting an empty string into a table in Informix Online Worgroup Server 7.12 running on Sun Solaris 2.5.1. I am using this SQL statement: UPDATE product_info SET prod_id = 1, prod_type_info_id = 1,short_description = 'Test', url = '', sort_order = 1 WHERE prod_info_id=1; The field "url" should be set to an empty string, but every time this statement is executed, the "url" field has a single space in it: ' '. I do not have anything special set on this field. It accepts nulls and does not default to anything. Here is the table definition: create table "informix".product_info ( prod_info_id serial not null constraint "informix".n120_59, prod_id integer, prod_type_info_id integer, description text, short_description varchar(50), url varchar(254), sort_order integer, primary key (prod_info_id) constraint "informix"._106_prom1 ); alter table "informix".product_info add constraint (foreign key (prod_id) references "informix".products constraint "informix".fk_pi_prod_id); alter table "informix".product_info add constraint (foreign key (prod_type_info_id) references "informix".product_type_info constraint "informix".fk_pi_pti_id); What would be causing this to happen? I don't think this is just a problem with this table. I think it is happening in other inserts and updates to different tables and fields as well. Thanks for the help, Tauren