Permission denied errors

Hello all, I woke up this morning and found my installation of Postgres
(7.3.2) spewing the following error message:

ERROR:  cannot count blocks for ev_log -- open failed: Permission denied
ERROR:  cannot count blocks for ev_log -- open failed: Permission denied
ERROR:  cannot count blocks for ev_log -- open failed: Permission denied
ERROR:  cannot count blocks for ev_log -- open failed: Permission denied

Now it seems as though the database is somehow diseased.  I can select and
insert data in all of the other tables in the database but I can not
create tables:

#  create table test_tab (idfield int);
ERROR:  cannot create test_tab: Permission denied

I also can not dump data out of ev_log:

pg_dump: ERROR:  cannot count blocks for ev_log -- open failed: Permission
denied
pg_dump: lost synchronization with server, resetting connection
pg_dump: SQL command to dump the contents of table "ev_log" failed:
PQendcopy() failed.
pg_dump: Error message from server: pg_dump: The command was: COPY
public.ev_log (logid, eventtype, username, ipaddress, eventdata, ts) TO
stdout;

Any ideas?

I'm willing to dump and reload, but I'd like to get the data out of the
log table if possible.

-Zeki