Error: Unable to look up type id 0

Hello,

I´m using PostgreSQL 7.3.2 and i´m having a little problem.

Error: Unable to look up type id 0

This error happens when I try to update a record on the table. I can
solve this if a drop the table and create it again, but how can I solve
this problem whitout need to do this? Any idea?

Thanks.

Rogério Augusto Bassete
Brazil - São Paulo