Fwd: db seems to be corrupt but continues to work. It won't let me do a pg_dump

Hello,

I've a db named "4unrealers". It has been running smoothly until yesterday.
While I was revising the backup process[1] I noticed this message:

dharana(at)triton:~$ pg_dump -c 4unrealers
getTableAttrs(): SELECT (for DEFAULT) for attr fmid returned 0 tuples. Expected 1.

Then I tried the following:

dharana(at)triton:~$ psql 4unrealers
Welcome to psql, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
\h for help with SQL commands
\? for help on internal slash commands
\g or terminate with semicolon to execute query
\q to quit

4unrealers=# \d forums_messages
PQgetvalue: ERROR! tuple number 0 is out of range 0..-1
Violación de segmento (Segmentation Fault)
dharana(at)triton:~$ pq_recvbuf: unexpected EOF on client connection

So I thought I lost the db but then tried:

dharana(at)triton:~$ psql 4unrealers
Welcome to psql, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
\h for help with SQL commands
\? for help on internal slash commands
\g or terminate with semicolon to execute query
\q to quit

4unrealers=# select count(fmid) from forums_messages;
NOTICE: AttrDefaultFetch: 2 record not found for rel forums_messages
count
-------
1761

\d works for others tables in the same db.

I've searched Recovery info in postgresql doc but I've found the pages relating
Recovering Dbs empty. Also google didn't threw a light about: NOTICE:
AttrDefaultFetch:.

Sysinfo:
Hardware
P133MMX + 96Mb RAM 20 Gb IDE

Software
PostgreSql 7.1.3 (from .deb) running on Debian Woody with kernel 2.4.17.

Any Ideas on how to proceed?

Thank you in advance.

--
dharana <dharana(at)dharana(dot)net> Black holes are where
PGP KeyID: 0xC32A724 GOD is dividing by zero