(Oops.)

src/view-text.el

@@ -448,7 +448,7 @@ unless we are reviewing without conversion. More precisely, the latin
 useful function to put in your `kom-view-text-hook'."
   (let* ((cti (lyskom-get-aux-item
 	       (text-stat->aux-items lyskom-view-text-text-stat) 1))
-         (content-type (and cti (aux-item->data (car cti)))))
+         (content-type (if cti (aux-item->data (car cti)) "")))
     (when (and (string-match "charset\\s-*=\\s-*utf-?8" content-type)
 	       (not (lyskom-viewing-noconversion)))
       (let* ((was (aref (cdr lyskom-view-text-text) 1)) ; original text version