Little fix to ASCII exporter with regards to [@start:num] structures.

lisp/org-ascii.el

@@ -571,9 +571,8 @@ publishing directory."
       (replace-match "\\1\\2")))
   ;; Remove list start counters
   (goto-char (point-min))
-  (while (re-search-forward  "\\[@start:[0-9]+\\] ?" nil t)
-    (org-if-unprotected
-     (replace-match "")))
+  (while (org-search-forward-unenclosed  "\\[@start:[0-9]+\\][ \t]*" nil t)
+    (replace-match ""))
   (remove-text-properties
    (point-min) (point-max)
    '(face nil font-lock-fontified nil font-lock-multiline nil line-prefix nil wrap-prefix nil)))