SQL & PL/SQL :: Incorrect LEFT JOIN Results In 11gR2?

We just upgraded to 11g and have run into incorrect results for some of our LEFT JOINs. If the table, view, subquery, or WITH clause that is being LEFT JOINed to contains any constants, the results are not correct.

For example, a test (nonsensical) view such as the following is created:

create or replace view fyvtst1 as
select spriden_pidm as fyvtst1_pidm,
'Sch' as fyvtst1_test
from spriden
where spriden_last_name like 'Sch%' ;

When I run the following query, I get correct results; that is, only those with "Sch" starting their last name are listed.

select spriden_pidm, spriden_last_name, fyvtst1_pidm, fyvtst1_test
from spriden
join fyvtst1 on fyvtst1_pidm = spriden_pidm ;

However, when I change the JOIN to a LEFT JOIN, the last column contains "Sch" for all rows, instead of NULL:

select spriden_pidm, spriden_last_name, fyvtst1_pidm, fyvtst1_test
from spriden
left join fyvtst1 on fyvtst1_pidm = spriden_pidm ;

We've discovered other quirky things related to this. A WITH clause with similar logic as the above view, when LEFT JOINed to a table will also cause the constant to appear in each row, instead of NULL (and only the value where there is a join). But when additional columns are added to the WITH, it behaves correctly.

This is easy enough to rewrite - but we have WITHs and views containing constants in numerous places, and cannot hope to track down every single one successfully before the incorrect results are used.

Finally, the NO_QUERY_TRANSFORMATION hint will force the query to work correctly. Unfortunately, it has a huge negative performance impact (one query ran for an hour, vs. 1 second in 10g).