Backend closed the channel unexpectedly

Hello,

I'm using PostgreSQL 6.5.1 on Linux RedHat 5.2 on a production server.

When I try to acces the data from the table "datos_insaculados",
this is the output:

redife=> select count(*) from datos_insaculados;
pqReadData() -- backend closed the channel unexpectedly.
        This probably means the backend terminated abnormally
        before or while processing the request.
We have lost the connection to the backend, so further processing is
impossible.  Terminating.

What's happening?  My table is corrupted or somenthing?
What can I do for solve this?

I hope you can help me.
Thanks in advance,
Marco A. Bravo