diff --git a/sleekxmpp/stanza/presence.py b/sleekxmpp/stanza/presence.py
index 651bf34..7eb0c5b 100644
--- a/sleekxmpp/stanza/presence.py
+++ b/sleekxmpp/stanza/presence.py
@@ -78,7 +78,9 @@ class Presence(RootStanza):
         Arguments:
             show -- Must be one of: away, chat, dnd, or xa.
         """
-        if show in self.showtypes:
+        if show is None:
+            self._delSub('show')
+        elif show in self.showtypes:
             self._setSubText('show', text=show)
         return self
 
@@ -99,6 +101,14 @@ class Presence(RootStanza):
             self['show'] = value
         return self
 
+    def delType(self):
+        """
+        Remove both the type attribute and the <show> element.
+        """
+        self._delAttr('type')
+        self._delSub('show')
+
+
     def setPriority(self, value):
         """
         Set the entity's priority value. Some server use priority to
diff --git a/sleekxmpp/xmlstream/stanzabase.py b/sleekxmpp/xmlstream/stanzabase.py
index f4a7e50..6851333 100644
--- a/sleekxmpp/xmlstream/stanzabase.py
+++ b/sleekxmpp/xmlstream/stanzabase.py
@@ -423,7 +423,9 @@ class ElementBase(object):
                     self._delAttr(attrib)
         elif attrib in self.plugin_attrib_map:
             if attrib in self.plugins:
+                xml = self.plugins[attrib].xml
                 del self.plugins[attrib]
+                self.xml.remove(xml)
         return self
 
     def _setAttr(self, name, value):
@@ -511,7 +513,7 @@ class ElementBase(object):
         element = self.xml.find(name)
 
         if not text and not keep:
-            return self.__delitem__(name)
+            return self._delSub(name)
 
         if element is None:
             # We need to add the element. If the provided name was
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_stanza_element.py b/tests/test_stanza_element.py
index c157e0a..2a774d6 100644
--- a/tests/test_stanza_element.py
+++ b/tests/test_stanza_element.py
@@ -607,7 +607,7 @@ class TestElementBase(SleekTest):
           <foo xmlns="foo">
             <foobar qux="a" />
           </foo>
-        """)
+        """, use_values=False)
         self.failUnless(len(stanza) == 1,
             "Incorrect stanza size with 1 substanza.")
 
@@ -617,7 +617,7 @@ class TestElementBase(SleekTest):
             <foobar qux="a" />
             <foobar qux="b" />
           </foo>
-        """)
+        """, use_values=False)
         self.failUnless(len(stanza) == 2,
             "Incorrect stanza size with 2 substanzas.")
 
@@ -627,7 +627,7 @@ class TestElementBase(SleekTest):
           <foo xmlns="foo">
             <foobar qux="b" />
           </foo>
-        """)
+        """, use_values=False)
 
         # Test iterating over substanzas
         stanza.append(substanza1)
diff --git a/tests/test_stanza_error.py b/tests/test_stanza_error.py
index f76ac62..d5ed6f5 100644
--- a/tests/test_stanza_error.py
+++ b/tests/test_stanza_error.py
@@ -30,11 +30,13 @@ class TestErrorStanzas(SleekTest):
 
         self.failUnless(msg['error']['condition'] == 'item-not-found', "Error condition doesn't match.")
 
-        del msg['error']['condition']
+        msg['error']['condition'] = 'resource-constraint'
 
         self.check_message(msg, """
           <message type="error">
-            <error type="cancel" />
+            <error type="cancel">
+              <resource-constraint xmlns="urn:ietf:params:xml:ns:xmpp-stanzas" />
+            </error>
           </message>
          """)
 
@@ -52,6 +54,6 @@ class TestErrorStanzas(SleekTest):
               <text xmlns="urn:ietf:params:xml:ns:xmpp-stanzas">Error!</text>
             </error>
           </message>
-        """)
+        """, use_values=False)
 
 suite = unittest.TestLoader().loadTestsFromTestCase(TestErrorStanzas)
diff --git a/tests/test_stanza_gmail.py b/tests/test_stanza_gmail.py
index 5c31a4e..a5630e6 100644
--- a/tests/test_stanza_gmail.py
+++ b/tests/test_stanza_gmail.py
@@ -25,7 +25,7 @@ class TestGmail(SleekTest):
                    newer-than-tid="11134623426430234"
                    q="is:starred" />
           </iq>
-        """)
+        """, use_values=False)
 
     def testMailBox(self):
         """Testing reading from Gmail mailbox result"""