wrong results at using ltree

I think I found a bug in the ltree module. The following query should
return false but I get true.

SELECT '5.0.1.0'::ltree ~ '5.!0.!0.0'::lquery

I get the same result with the 'ltree.dll' of PostgreSQL 8.2.5. If you
have a solution of the problem I would be very happy.