请教emacs session.el问题

bcjr

debian emacs21.4.1
我的.emacs为：
(setq current-language-environment "Chinese-GBK")
(set-keyboard-coding-system 'chinese-iso-8bit)
(prefer-coding-system 'gb2312)
(global-font-lock-mode t)
(tool-bar-mode 0)
(setq delete-auto-save-files t)

        ;session.el
(require 'session)
(add-hook 'after-init-hook 'session-initialize)
(setq session-save-file "~/.session")
       
;;setnu.el
(require 'setnu)
(setnu-mode t)
;; ido.el
(require 'ido)
(ido-mode t)
;; ibuffer.el
(require 'ibuffer)
(global-set-key (kbd "C-x C-b") 'ibuffer)
;;desktop.el embeded in emacs,it should be placed at the last of all the el file
(load "desktop")
(desktop-load-default)
(desktop-read)
;; enable copy &paste between application and emacs
(setq x-select-enable-clipboard t)
(setq interprogram-paste-function 'x-cut-buffer-or-selection-value)
       
session 的menu怎么也不出来,kill-ring也保存不了,.session一直为空？不知为何？请大虾赐教！谢谢