diff -r c2910971eb86 Lib/idlelib/AutoComplete.py
--- a/Lib/idlelib/AutoComplete.py	Mon Jun 11 17:56:08 2012 +0100
+++ b/Lib/idlelib/AutoComplete.py	Tue Jun 12 14:46:00 2012 -0500
@@ -140,7 +140,7 @@
         elif hp.is_in_code() and (not mode or mode==COMPLETE_ATTRIBUTES):
             self._remove_autocomplete_window()
             mode = COMPLETE_ATTRIBUTES
-            while i and curline[i-1] in ID_CHARS or ord(curline[i-1]) > 127:
+            while i and (curline[i-1] in ID_CHARS or ord(curline[i-1]) > 127):
                 i -= 1
             comp_start = curline[i:j]
             if i and curline[i-1] == '.':