Problem with PreparedStatement

I'm trying to do this:

if (counter != -1) /* No ha habido ningún error */
{
PreparedStatement pstmt=null;
sql="insert into tar_historico values (?,?,?)";
razon="<br>Query: " + sql;
try {
pstmt = con.prepareStatement(sql);
pstmt.setString(1,Integer.toString(counter));
pstmt.setString(2,"1");
pstmt.setTimestamp(3,new Timestamp(new
java.util.Date().getTime()));
pstmt.executeUpdate(sql);
pstmt.close();
con.close();
}

But I get this error message in the PostgreSQL log:

query: insert into tar_historico values (?,?,?)
ERROR: parser: parse error at or near ","

What could be the problem? I've tried everything and I haven't found the
solution yet. Please, help.
Thanks in advance,

Esteban Chiner
------------------------------------------------------------
Esteban Chiner Sanz mailto (work): echiner(at)tissat(dot)es
TISSAT
Av. Aragon, 30, 5ª planta Phone: 96 393 9950
Valencia (SPAIN)