diff --git a/ORGWEBPAGE/Changes.org b/ORGWEBPAGE/Changes.org
index 3b00b8dcb..1e6ebcc86 100644
--- a/ORGWEBPAGE/Changes.org
+++ b/ORGWEBPAGE/Changes.org
@@ -16,6 +16,15 @@
 :END:
 
 ** Overview
+** Incompatible changes
+*** New structure for the timestamp directory for org-publish.
+    The timestamp directory now uses SHA1 hashed versions of the
+    path to each publishing file.  This should be a consistent
+    and system-independent way to handle things.  The change
+    means that your next publishing command will publish each and
+    every file again, but just once, until the timestamps are
+    updated.
+
 ** Details
 
 *** New parameters :prefix and :prefix1 for include files
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 2935e6cbf..aaad42363 100755
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2008-07-07  Carsten Dominik  <dominik@science.uva.nl>
+
+	* org-publish.el (org-publish-timestamp-filename): Use
+	SHA1-encoded file names in the timestamp directory.
+
 2008-07-05  Carsten Dominik  <dominik@science.uva.nl>
 
 	* org-publish.el (org-publish-needed-p): Be verbose about files
diff --git a/lisp/org-publish.el b/lisp/org-publish.el
index b1aa6777c..f7dbf19ab 100644
--- a/lisp/org-publish.el
+++ b/lisp/org-publish.el
@@ -297,10 +297,8 @@ If functions in this hook modify the buffer, it will be saved."
 
 (defun org-publish-timestamp-filename (filename)
   "Return path to timestamp file for filename FILENAME."
-  (while (string-match
-	  (if (eq system-type 'windows-nt) "~\\|/\\|:" "~\\|/") filename)
-    (setq filename (replace-match "_" nil t filename)))
-  (concat org-publish-timestamp-directory filename ".timestamp"))
+  (concat (file-name-as-direcory org-publish-timestamp-directory)
+         "X" (if (fboundp 'sha1) (sha1 filename) (md5 filename))))
 
 (defun org-publish-needed-p (filename)
   "Return `t' if FILENAME should be published."