Hi! Folks I am running Emacs 23.3.1 on Ubuntu 12.04 32bit. I tried to run `dired' on my Emacs extension directory and marked some files by `dired-mark-extension', and then I want to revert the mark and remove in-interesting file lines from the dired buffer, so I ran `dired-mark-unmarked-files' command, it failed with exceptions. Below is messages from the *Message* buffer. For information about GNU Emacs and the GNU system, type C-h C-a. Quit [2 times] Making completion list... Quit Making completion list... Loading dired-x...done Marking matching files... 16 matching files marked. call-interactively: Wrong number of arguments: #[(regexp msg &optional unflag-p localp) ("/usr/share/emacs/23.3/lisp/dired-x.elc" . 18095) nil 9 ("/usr/share/emacs/23.3/lisp/dired-x.elc" . 17750) "P"], 1 GNU Emacs 23.3.1 (i686-pc-linux-gnu, GTK+ Version 2.24.10) of 2012-03-26 on roseapple, modified by Debian I enabled debug by (toggle-debug-on-error) and ran the command `dired-mark-unmarked-files ' again. And the *Backtrace* buffer displayed following messages. Debugger entered--Lisp error: (wrong-number-of-arguments #[(regexp msg &optional unflag-p localp) ("/usr/share/emacs/23.3/lisp/dired-x.elc" . 18095) nil 9 ("/usr/share/emacs/23.3/lisp/dired-x.elc" . 17750) "P"] 1) dired-mark-unmarked-files(nil) call-interactively(dired-mark-unmarked-files t nil) execute-extended-command(nil) call-interactively(execute-extended-command nil nil) It seems like that `dired-mark-unmarked-files ' would need some parameters but it is not provided. Will anyone help me? Thanks a lot. -- M-x Thinks