drop constraint problem

Hi all,

i'm running 7.2.1 and have problems with dropping constraints:

fakt32=# alter table wkfaktzeilen
add constraint printjobfk foreign key (printjob)
references wkfaktdruck(printjob)
match full
on delete cascade
on update cascade;
>ALTER

fakt32=# alter table wkfaktzeilen drop constraint printjobfk restrict;
>ERROR: ALTER TABLE / DROP CONSTRAINT: printjobfk does not exist

fakt32=# alter table wkfaktdruck drop constraint printjobfk restrict;
>ERROR: ALTER TABLE / DROP CONSTRAINT: printjobfk does not exist

but when dropping the table, the triggers are deleted and i can see the
entries
in pg_triggers??

please help
Wolfgang