Erase buffer for txt export.

lisp/ChangeLog

@@ -1,3 +1,7 @@
+2008-09-02  Carsten Dominik  <dominik@science.uva.nl>
+
+	* org-agenda.el (org-write-agenda): Erase buffer for txt export.
+
 2008-09-01  Carsten Dominik  <dominik@science.uva.nl>
 
 	* org-exp.el (org-html-do-expand): Allow {} to terminate

lisp/org-agenda.el

@@ -1879,6 +1879,7 @@ higher priority settings."
 	  (t
 	   (let ((bs (buffer-string)))
 	     (find-file file)
+	     (erase-buffer)
 	     (insert bs)
 	     (save-buffer 0)
 	     (kill-buffer (current-buffer))