@@ -276,11 +276,11 @@
         return False
 
     def isValid (self, sWord):
         "checks if <sWord> is valid (different casing tested if the first letter is a capital)"
         if not sWord:
-            return None
+            return True
         if "'" in sWord: # ugly hack
             sWord = sWord.replace("'", "’")
         if self.lookup(sWord):
             return True
         if sWord[0:1].isupper():