Very strange Error in Updates

I found a very strange error/behavior in a PreparedStatement  for a
simple SQL Update over a VARCHAR field.
The code is like:

    Statement stmt = con.createStatement();
    PreparedStatement pstIns = con.prepareStatement("update userid.t set
calle = ? ");
    ResultSet rs = stmt.executeQuery( "select calle from userid.t2" );
    while ( rs.next() ) {
                pstIns.clearParameters();
                String x = rs.getString("CALLE");
                pstIns.setString(1, x );
                int nrows = pstIns.executeUpdate();
                System.out.println( "Filas afectadas "+ nrows );
     }


When the parameter fill the full-length of  receiving field and has any
non common character, the update throw a exception like:

java.sql.SQLException: ERROR:  value too long for type character varying(30)
    at
org.postgresql.core.v2.QueryExecutorImpl.receiveErrorMessage(QueryExecutorImpl.java:420)
    at
org.postgresql.core.v2.QueryExecutorImpl.processResults(QueryExecutorImpl.java:345)
    at
org.postgresql.core.v2.QueryExecutorImpl.execute(QueryExecutorImpl.java:251)
    at
org.postgresql.core.v2.QueryExecutorImpl.execute(QueryExecutorImpl.java:159)
    at
org.postgresql.jdbc1.AbstractJdbc1Statement.execute(AbstractJdbc1Statement.java:342)
    at
org.postgresql.jdbc1.AbstractJdbc1Statement.executeWithFlags(AbstractJdbc1Statement.java:290)
    at
org.postgresql.jdbc1.AbstractJdbc1Statement.executeUpdate(AbstractJdbc1Statement.java:245)
    at
com.sistemat.app.rsmaster.reloadable.RepImportar.PrDw_Cuentas(RepImportar.java:2471)
    at
com.sistemat.app.rsmaster.reloadable.RepImportar.Importar(RepImportar.java:260)
    at
com.sistemat.app.rsmaster.reloadable.RepMasterImpl.Ciclo_Replicacion(RepMasterImpl.java:955)
    at
com.sistemat.app.rsmaster.reloadable.RepMasterImpl.runWorker(RepMasterImpl.java:748)
    at
com.sistemat.app.rsmaster.reloadable.RepMasterImpl.run(RepMasterImpl.java:427)
    at java.lang.Thread.run(Unknown Source)

This field/value produce the Exception:   CALLE=[ENFERMERA CLEMON. B§
ALTO ALBR]

If this field is changed to:                        CALLE=[ENFERMERA
CLEMON. B# ALTO ALBR]
then  the update is performed without
any problem.

Although the first value can be Inserted  with a prepared statement
without problems.

A have no explanation to this case , and any help will be appreciated.

Dario Fassi.