Question About Ansi_nulls

Hi,
I figure that my query below should return the records that I've inserted into test1 and test2 after I turn ansi_nulls off for my session. But the query does not return any records. Any ideas?

create table test1 (id int, create_date datetime null)
create table test2 (id int, create_date datetime null)

insert test1 values (1,null)
insert test2 values (1,null)

set ansi_nulls off

select *
from test1 t1 join test2 t2 on t1.id = t2.id
where t1.create_date = t2.create_date