pg_dump fails pg_rewrite entry not found

Hello, our database suddenly went broken somehow. We still dont know if
it is becouse of hw failure etc., anyway, when I try to make dump using
pg_dump or pg_dumpall I have got error message like this:

pg_dump: failed sanity check, parent table OID 1001834 of pg_rewrite
entry OID 1001837 not found
pg_dumpall: pg_dump failed on database "eb3_nz", exiting

I have tried to search for such an error and have found a lot of
solution suggestions, but nothing worked for me, because I did not found
any record in pg_class, or pg_rewrite, etc. referencing to those OIDs
1001834 or 1001837 . The version of postgres is 9.2.2

Please is there any other place, where to look for the error?

Thank you in advance,
Jakub.