Problems with pg_dump

Hello!
               I try to do this:
                        pg_dump mydb -C -s -f out.sql

               but it happens the following error:
                    getTables(): SELECT (for PRIMARY KEY) failed on
table clientes.  Explanation from backend: ERROR:  dtoi4: integer out of
range

                I review, but data is ok.

                            Thanks for all.
                                    Alberto