Spring JdbcTemplate returns empty result when there should be a valid result

Question

I'm using SimpleJdbcDaoSupport object to access DB resources. I have a query which is frequently executed against the database to locate a record with a specific key. for some reason after executing the same query several times I start to get an empty result even though the record exists in the database.

Any ideas what can cause this behavior?

daoSupport.getJdbcTemplate().query(this.getConsumerTokenQueryStatement(),params, this.rowMapper); 
 public static class TokenServicesRowMapper implements RowMapper {  
   public Object mapRow(ResultSet rs, int rowNum) throws SQLException { 
     DefaultLobHandler lobHandler = new DefaultLobHandler(); 
     return lobHandler.getBlobAsBytes(rs, 1); 
   } 
}