Andreas Schmitz <a.schmitz@cityweb.de> writes:
>> What PG version is this?
> PostgreSQL 7.4.1 is used in this case.
Now that I look at it, your report matches Chris K-L's trouble
http://archives.postgresql.org/pgsql-hackers/2004-01/msg00530.php
which is fixed in 7.4.2.
regards, tom lane