select statement fails

Any idea why the following select statement does not return rows ?
This select statement is generated by npgsql2 beta 3 so I cannot change it
in my application.
How to fix without changing select statement ?

Andrus.

create temp table test ( tc char(1) );
insert into test values(' ');
select * from test where tc=' '::text;

Using

"PostgreSQL 8.3beta4, compiled by Visual C++ build 1400"