--- nnml.el~	2010-12-21 17:33:07.000000000 +0800
+++ nnml.el	2010-12-21 17:33:09.000000000 +0800
@@ -235,7 +235,11 @@
 			  (nnheader-article-to-file-alist
 			   (setq gpath (nnml-group-pathname (car group-num)
 							    nil server))))))
-	  (setq path (concat gpath (int-to-string (cdr group-num)))))
+	  (nnml-update-file-alist)
+	  (setq path (concat gpath  (if nnml-use-compressed-files
+					(cdr (assq (cdr group-num)
+						   nnml-article-file-alist))
+				      (number-to-string (cdr group-num))))))
       (setq path (nnml-article-to-file id)))
     (cond
      ((not path)