Erro hibernate

o erro…

abriu transação
inseriu
Hibernate: /* insert hibernate.TbEventos */ insert into IBICT_FS.TB_EVENTOS (EVE_NOME, EVE_SIGLA, EVE_DT_INSC_INICIO, EVE_DT_INSC_FIM, EVE_URL, EVE_LOCAL, EVE_TEMA, EVT_ID, EVE_ID_PARALELO, ARC_CODIGO, PAIS_SIGLA, UF_REGIAO, UF_SIGLA, EVE_SITUACAO, EVE_DT_INICIO, EVE_DT_FIM, EVE_AUTORIZA_WEB, EVE_CARGA_HORARIA, EVE_OBS, INS_ID, EVE_CIDADE, EVE_ABRANGENCIA, EVE_RESPONSAVEL, USB_ID, EVE_NR, EVE_DT_INCLUSAO, EVE_ID) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
2006-07-21 10:08:52,156 WARN  struts.action.RequestProcessor  -> Unhandled Exception thrown: class java.lang.ClassCastException
2006-07-21 10:08:54,078 WARN  hibernate.jdbc.ConnectionManager  -> unclosed connection, forgot to call close() on your session?
2006-07-21 10:08:54,078 WARN  hibernate.jdbc.ConnectionManager  -> unclosed connection, forgot to call close() on your session?

o metodo que salva

 public  void inserir(TbEventos evento){
    	Session sessao = HibernateUtility.getSession();
		Transaction tx = sessao.beginTransaction();
		System.out.println("abriu transação");
		sessao.save(evento);
		System.out.println("inseriu");
		tx.commit();
		System.out.println("comit");
		sessao.close();
    }

Obrigado