Remove the test file before writing it in case there is no write permission.
This might help fix some of the failures on Windows box(es).  It doesn't hurt
either way and ensure the tests are a little more self contained (ie have
less assumptions).
diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py
index a185f78..0b751d8 100644
--- a/Lib/test/test_deque.py
+++ b/Lib/test/test_deque.py
@@ -63,6 +63,7 @@
         self.assertEqual(list(d), range(7, 10))
         d = deque(xrange(200), maxlen=10)
         d.append(d)
+        test_support.unlink(test_support.TESTFN)
         fo = open(test_support.TESTFN, "wb")
         try:
             print >> fo, d,
@@ -281,6 +282,7 @@
     def test_print(self):
         d = deque(xrange(200))
         d.append(d)
+        test_support.unlink(test_support.TESTFN)
         fo = open(test_support.TESTFN, "wb")
         try:
             print >> fo, d,