As superuser I still can't update a row in one table

Good morning all,

I have a postgresql database used by redhat's spacewalk system that we've
been upgrading. The database's schema-upgrade script failed during our
attempt and I'm trying to clean up. The script errored on the very last
function it tries,and that one invokes another function which is the actual
problem. I altered this function, and got it to write values to it's table,
but they're the wrong values. So now, I'm trying to just run some simple
updates on the table and this is failing.

I'm logged into the database as a Superuser. Here's the sequence from psql:

rhnschema=# \du s45198
List of roles
Role name | Attributes | Member of
-----------+------------+-----------
s45198 | Superuser | {}

rhnschema=# grant all on schema public to s45198;
GRANT
rhnschema=# grant all on all tables in schema public to s45198;
GRANT
rhnschema=# grant all on table public.rhnpackageevr to s45198;
GRANT
rhnschema=# update rhnpackageevr set epoch = null where id = 19263;
ERROR: Permission denied: UPDATE is not allowed on rhnpackageevr

The grants I tried to add should have been unnecessary, but how can I, as a
Superuser, still be denied the ability to update a table?
--
Jay