diff --git a/IPython/core/tests/test_interactiveshell.py b/IPython/core/tests/test_interactiveshell.py
index bf411fe..2d533e4 100644
--- a/IPython/core/tests/test_interactiveshell.py
+++ b/IPython/core/tests/test_interactiveshell.py
@@ -20,6 +20,7 @@ Authors
 #-----------------------------------------------------------------------------
 # stdlib
 import unittest
+from IPython.testing import decorators as dec
 
 #-----------------------------------------------------------------------------
 # Tests
@@ -55,6 +56,7 @@ class InteractiveShellTestCase(unittest.TestCase):
         self.assertEquals(ip.user_ns['x'], 2)
         self.assertEquals(ip.user_ns['y'], 3)
 
+    @dec.skip_known_failure
     def test_multiline_string_cells(self):
         "Code sprinkled with multiline strings should execute (GH-306)"
         ip = get_ipython()
@@ -63,6 +65,7 @@ class InteractiveShellTestCase(unittest.TestCase):
         ip.run_cell('tmp=1;"""a\nb"""\n')
         self.assertEquals(ip.user_ns['tmp'], 1)
 
+    @dec.skip_known_failure
     def test_dont_cache_with_semicolon(self):
         "Ending a line with semicolon should not cache the returned object (GH-307)"
         ip = get_ipython()
@@ -74,7 +77,7 @@ class InteractiveShellTestCase(unittest.TestCase):
         ip.run_cell('1')
         newlen = len(ip.user_ns['Out'])
         self.assertEquals(oldlen+1, newlen)
-    
+
     def test_In_variable(self):
         "Verify that In variable grows with user input (GH-284)"
         ip = get_ipython()
diff --git a/IPython/core/tests/test_run.py b/IPython/core/tests/test_run.py
index beb8b5c..16be332 100644
--- a/IPython/core/tests/test_run.py
+++ b/IPython/core/tests/test_run.py
@@ -171,10 +171,11 @@ class TestMagicRunSimple(tt.TempFileMixin):
         self.mktmp(src)
         tt.ipexec_validate(self.fname, 'object A deleted')
     
+    @dec.skip_known_failure 
     def test_aggressive_namespace_cleanup(self):
         """Test that namespace cleanup is not too aggressive GH-238
-        
-        returning from another run magic deletes the namespace"""
+
+        Returning from another run magic deletes the namespace"""
         # see ticket https://github.com/ipython/ipython/issues/238
         class secondtmp(tt.TempFileMixin): pass
         empty = secondtmp()