BUG #1454: error in "select * from table where a1 like '%\%%' " ???

The following bug has been logged online:

Bug reference:      1454
Logged by:          Ricky
Email address:      ricky@ez2.us
PostgreSQL version: 8.0
Operating system:   Mandrake Linux 10.1
Description:        error in "select * from table where a1 like '%\%%' " ???
Details:

I perform a query to get data,which contains '%'.
so I do this query.
select * from table where a1 like '%\%%';
but it returns all rows.
then I do another query.
select * from table where a1 like '\%';
but it still return all rows.
like "select * from table"