Problemas con XHTML 1.0

[Reynier]

Código PHP:

  <tr>
                        <td valign="top" align="right">Informaci&oacute;n extra:</td>
                        <td align="left"><textarea name="uextrainformacion" cols="50" rows="5" wrap="VIRTUAL" id="uextrainformacion"></textarea></td>
                      </tr>
                      <tr>
                        <td valign="top" align="right">Firma:</td>
 
                        <td align="left">
                         <textarea name="ufirma" cols="50" rows="5" wrap="VIRTUAL" id="ufirma"></textarea>
                        </td>
                      </tr>
                      <tr>
                        <td colspan="2" align="center"><hr class="hr"/></td>
                      </tr>
                      <tr>
                        <td colspan="2">
 
                         <input name="umailpublic" checked type="checkbox" id="umailpublic" value="1"/>Mostrar correo p&uacute;blico
                        </td>
                        </tr>
                      <tr>
                        <td colspan="2"><input name="usign" checked type="checkbox" id="usign" value="1"/>Usar firma en todos los mensajes</td>
                      </tr>
                      <tr>
                        <td colspan="2"><input name="ureceiveboletin" checked type="checkbox" id="ureceiveboletin" value="1"/>Recibir bolet&iacute;n del Portal por correo electr&oacute;nico</td>
 
                      </tr>
                      <tr>
                        <td colspan="2">
                         <input name="unotifiymail" type="checkbox" id="unotifiymail" value="1"/>Notificar mensajes privados y/o respuestas mediante correo electr&oacute;nico
                        </td>
                        </tr>
                      <tr>
                        <td colspan="2" align="right"><hr class="hr"/></td>
                        </tr>
 
                      <tr>
                        <td align="right">Avatar de Usuario:</td>
                        <td align="left"><input name="uavataruploaded" type="file" id="uavataruploaded" size="35"/></td>
                      </tr>
                      <tr>
                        <td colspan="2" align="center"><hr class="hr"/></td>
                      </tr>
                      <tr>
 
                        <td colspan="2" align="center"><input name="ubtn_send" type="button" id="ubtn_send" value="Continuar :&gt;" onclick="javascript:return validateForm();"  /></td>
                    </tr>
                    </table>
                </form>
                </td>
            </tr>
        </table>
    </td>
</tr>     <tr>
 
   <td align="center" class="topnav" colspan="2">Todos los derechos reservados &copy; 2005 - Joven Club de Computaci&oacute;n y Electr&oacute;nica de Granma</td>
 </tr>
</table>
</body>
</html>