Cannot open segment 1

Hi, I've got troubles today with my db, my postmaster freeses at every
10-15 minutes. I looked to the logs, and I've found the next error:
ERROR:  cannot open segment 1 of relation pg_proc_oid_index

and sometimes it is followed by:
ERROR:  SearchSysCache: recursive use of cache 9

It seems to me, that there's some corruption in the pg_proc_oid_index
relation, but I don't know how to correct it, becouse it's a system index,
and I'm not allowed to drop it, and recreate it - I think this would be
the most easy... Now I'm in troubles, becouse id something want to access
this index relation, all my processes freeze in the startup phrase, I have
to kill the postmaster and start it again.

If someone experienced such things, plz elp me

+--------------------------------------------+
| Nagy Attila                                |
|   mailto:mrbig@sneaker.sch.bme.hu          |
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