Problem with database: FATAL 1: cannot find attribute 24 of relation

Help!

One of my customers is having a problem with their database causing all of
their sites to be down right now. The problem seems to effect only their
database, not any other databases on the server. Here is the output when
connecting to it:

[root(at)s1 data]# psql -U postgres dans_pgsql
Password:
Asql: FATAL 1: cannot find attribute 24 of relation

I've searched the email archives as well as deja.com, but cannot find this
error message mentioned anywhere. Does anyone know what it means? I've
tried restarting postgres. Can anyone help suggest what I can do to get
this database working again?

I have backups of all raw files on the server, but the customer has not done
a dump of their database recently. I rather doubt that restoring their
database from tape would replace it in a consistent state. Any thoughts on
this as well?

Thanks,
Tauren