diff --git a/yatex.el b/yatex.el
index 6a5f115..ce42042 100644
--- a/yatex.el
+++ b/yatex.el
@@ -1,15 +1,15 @@
 ;;; -*- Emacs-Lisp -*-
 ;;; Yet Another tex-mode for emacs - //�쒹//
-;;; yatex.el rev. 1.74.5
+;;; yatex.el rev. 1.74.6
 ;;; (c)1991-2011 by HIROSE Yuuji.[yuuji@yatex.org]
-;;; Last modified Thu Dec  1 23:00:13 2011 on firestorm
+;;; Last modified Thu Dec 15 13:37:47 2011 on firestorm
 ;;; $Id$
 ;;; The latest version of this software is always available at;
 ;;; http://www.yatex.org/
 
 (require 'comment)
 (require 'yatexlib)
-(defconst YaTeX-revision-number "1.74.5"
+(defconst YaTeX-revision-number "1.74.6"
   "Revision number of running yatex.el")
 
 ;---------- Local variables ----------
diff --git a/yatexlib.el b/yatexlib.el
index ea774ce..fccd06c 100644
--- a/yatexlib.el
+++ b/yatexlib.el
@@ -2,7 +2,7 @@
 ;;; YaTeX and yahtml common libraries, general functions and definitions
 ;;; yatexlib.el
 ;;; (c)1994-2009 by HIROSE Yuuji.[yuuji@yatex.org]
-;;; Last modified Thu Oct 13 09:36:20 2011 on firestorm
+;;; Last modified Thu Dec 15 13:37:26 2011 on firestorm
 ;;; $Id$
 
 ;; General variables
@@ -912,7 +912,7 @@
 		    (goto-char m0)
 		    (put 'YaTeX-inner-environment 'indent (current-column))
 		    (throw 'begin t)))))
-	  (buffer-substring
+	  (YaTeX-buffer-substring
 	   (progn (skip-chars-forward open) (1+ (point)))
 	   (progn (skip-chars-forward close) (point)))))))
 
@@ -998,9 +998,16 @@
   (let ((env (YaTeX-inner-environment)))
     (if (not env) (error "No premature environment")
       (save-excursion
-	(if (YaTeX-search-active-forward
-	     (YaTeX-replace-format-args YaTeX-struct-end env "" "")
-	     YaTeX-comment-prefix nil t)
+	(if (and
+	     (YaTeX-re-search-active-forward
+	      (concat
+	       "\\(" (YaTeX-replace-format-args
+		      YaTeX-struct-end env "" "")
+	       "\\)\\|\\(" (YaTeX-replace-format-args
+		      YaTeX-struct-begin env "" "")
+	       "\\)")
+	      YaTeX-comment-prefix nil t)
+	     (match-beginning 1))	;is closing struc.
 	    (if (y-or-n-p
 		 (concat "Environment `" env
 			 "' may be already closed. Force close?"))