diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 7ea8668d94c..b092bd93b74 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -683,6 +683,11 @@ def dash_R_cleanup(fs, ps, pic, abcs):
     import struct, filecmp
     from distutils.dir_util import _path_created
 
+    # Clear the warnings registry, so they can be displayed again
+    for mod in sys.modules.values():
+        if hasattr(mod, '__warningregistry__'):
+            del mod.__warningregistry__
+
     # Restore some original values.
     warnings.filters[:] = fs
     copy_reg.dispatch_table.clear()
diff --git a/Lib/test/test_frozen.py b/Lib/test/test_frozen.py
index e981fb3ddb7..4835e475f85 100644
--- a/Lib/test/test_frozen.py
+++ b/Lib/test/test_frozen.py
@@ -35,6 +35,10 @@ class FrozenTests(unittest.TestCase):
         self.assertEquals(stdout.getvalue(),
                           'Hello world...\nHello world...\nHello world...\n')
 
+        del sys.modules['__hello__']
+        del sys.modules['__phello__']
+        del sys.modules['__phello__.spam']
+
 
 def test_main():
     run_unittest(FrozenTests)
diff --git a/Lib/test/test_pkg.py b/Lib/test/test_pkg.py
index 4fa367f5600..3a954ca3663 100644
--- a/Lib/test/test_pkg.py
+++ b/Lib/test/test_pkg.py
@@ -46,12 +46,20 @@ class Test(unittest.TestCase):
 
     def setUp(self):
         self.root = None
+        self.pkgname = None
         self.syspath = list(sys.path)
 
     def tearDown(self):
         sys.path[:] = self.syspath
         cleanout(self.root)
 
+        # delete all modules concerning the tested hiearchy
+        if self.pkgname:
+            modules = [name for name in sys.modules
+                       if self.pkgname in name.split('.')]
+            for name in modules:
+                del sys.modules[name]
+
     def run_code(self, code):
         exec(textwrap.dedent(code), globals(), {"self": self})
 
@@ -74,6 +82,8 @@ class Test(unittest.TestCase):
                     f.write('\n')
                 f.close()
         self.root = root
+        # package name is the name of the first item
+        self.pkgname = descr[0][0]
 
     def test_1(self):
         hier = [("t1", None), ("t1 __init__"+os.extsep+"py", "")]
@@ -223,8 +233,8 @@ class Test(unittest.TestCase):
 
     def test_7(self):
         hier = [
-                ("t7"+os.extsep+"py", ""),
                 ("t7", None),
+                ("t7"+os.extsep+"py", ""),
                 ("t7 __init__"+os.extsep+"py", ""),
                 ("t7 sub"+os.extsep+"py",
                  "raise RuntimeError('Shouldnt load sub.py')"),
diff --git a/Lib/test/test_pkgutil.py b/Lib/test/test_pkgutil.py
index 4381f911bb4..a14f09187a5 100644
--- a/Lib/test/test_pkgutil.py
+++ b/Lib/test/test_pkgutil.py
@@ -48,6 +48,8 @@ class PkgutilTests(unittest.TestCase):
         res2 = pkgutil.get_data(pkg, 'sub/res.txt')
         self.assertEqual(res2, RESOURCE_DATA)
 
+        del sys.modules[pkg]
+
     def test_getdata_zipfile(self):
         zip = 'test_getdata_zipfile.zip'
         pkg = 'test_getdata_zipfile'
@@ -74,6 +76,8 @@ class PkgutilTests(unittest.TestCase):
         self.assertEqual(res2, RESOURCE_DATA)
         del sys.path[0]
 
+        del sys.modules[pkg]
+
 class PkgutilPEP302Tests(unittest.TestCase):
 
     class MyTestLoader(object):
diff --git a/Lib/test/test_profile.py b/Lib/test/test_profile.py
index c8281c34364..0bd2530cf2a 100755
--- a/Lib/test/test_profile.py
+++ b/Lib/test/test_profile.py
@@ -21,8 +21,9 @@ class ProfileTest(unittest.TestCase):
     def do_profiling(cls):
         results = []
         prof = cls.profilerclass(timer, 0.001)
+        start_timer = timer()
         prof.runctx("testfunc()", globals(), locals())
-        results.append(timer())
+        results.append(timer() - start_timer)
         for methodname in cls.methodnames:
             s = StringIO()
             stats = pstats.Stats(prof, stream=s)
@@ -33,7 +34,7 @@ class ProfileTest(unittest.TestCase):
 
     def test_cprofile(self):
         results = self.do_profiling()
-        self.assertEqual(results[0], 43000)
+        self.assertEqual(results[0], 1000)
         for i, method in enumerate(self.methodnames):
             self.assertEqual(results[i+1], self.expected_output[method],
                              "Stats.%s output for %s doesn't fit expectation!" %
diff --git a/Lib/test/test_structmembers.py b/Lib/test/test_structmembers.py
index a59cfa952f4..6c1a947fe3f 100644
--- a/Lib/test/test_structmembers.py
+++ b/Lib/test/test_structmembers.py
@@ -101,12 +101,6 @@ class TestWarnings(unittest.TestCase):
 
 
 def test_main(verbose=None):
-    # Obscure hack so that this test passes after reloads or repeated calls
-    # to test_main (regrtest -R).
-    if '__warningregistry__' in globals():
-        del globals()['__warningregistry__']
-    if hasattr(sys, '__warningregistry__'):
-        del sys.__warningregistry__
     test_support.run_unittest(__name__)
 
 if __name__ == "__main__":
diff --git a/Lib/test/test_warnings.py b/Lib/test/test_warnings.py
index fb6aabbd35d..9fca0802473 100644
--- a/Lib/test/test_warnings.py
+++ b/Lib/test/test_warnings.py
@@ -391,6 +391,8 @@ class PyWarningsDisplayTests(BaseTest, WarningsDisplayTests):
 
 
 def test_main():
+    py_warnings.onceregistry.clear()
+    c_warnings.onceregistry.clear()
     test_support.run_unittest(CFilterTests,
                                 PyFilterTests,
                                 CWarnTests,