diff -r 31fc3ff3e626 pypy/objspace/std/test/test_unicodeobject.py
--- a/pypy/objspace/std/test/test_unicodeobject.py	Mon Sep 26 17:50:09 2011 -0400
+++ b/pypy/objspace/std/test/test_unicodeobject.py	Wed Sep 28 02:14:18 2011 -0400
@@ -443,6 +443,7 @@
         assert u'<i><i><i>c' == u'abababc'.translate({ord('a'):None, ord('b'):u'<i>'})
         assert u'c' == u'abababc'.translate({ord('a'):None, ord('b'):u''})
         assert u'xyyx' == u'xzx'.translate({ord('z'):u'yy'})
+        assert u'abcd' == u'abcd'.translate(u'')

         raises(TypeError, u'hello'.translate)
         raises(TypeError, u'abababc'.translate, {ord('a'):''})
diff -r 31fc3ff3e626 pypy/objspace/std/unicodeobject.py
--- a/pypy/objspace/std/unicodeobject.py	Mon Sep 26 17:50:09 2011 -0400
+++ b/pypy/objspace/std/unicodeobject.py	Wed Sep 28 02:14:18 2011 -0400
@@ -893,7 +893,7 @@
         try:
             w_newval = space.getitem(w_table, space.wrap(ord(unichar)))
         except OperationError, e:
-            if e.match(space, space.w_KeyError):
+            if e.match(space, space.w_KeyError) or e.match(space, space.w_IndexError):
                 result.append(unichar)
             else:
                 raise