catalog is missing n attribute(s) for relid xxxx at character yy

Hi,
PostgreSQL 9.1 x86 on Windows 10 (EOL, but in this case it doesn't apply 
:-) )

When querying a table, I receive the error reported in subject:
catalog is missing 5 attribute(s) for relid 33238 at character 15

So I decided to drop and recreate the table.
DROP TABLE tbl;
same error.

Is there anything else I can do to avoid to drop and recreate the whole 
database?

Thanks
Moreno.-