diff --git a/paramiko/auth_transport.py b/paramiko/auth_transport.py
index b8468f0..1bc0f7d 100644
--- a/paramiko/auth_transport.py
+++ b/paramiko/auth_transport.py
@@ -48,6 +48,7 @@ class Transport (BaseTransport):
 
     def __init__(self, sock):
         BaseTransport.__init__(self, sock)
+        self.username = None
         self.authenticated = False
         self.auth_event = None
         # for server mode:
@@ -79,9 +80,21 @@ class Transport (BaseTransport):
 
         @return: True if the session is still open and has been authenticated successfully;
         False if authentication failed and/or the session is closed.
+        @rtype: bool
         """
         return self.authenticated and self.active
 
+    def get_username(self):
+        """
+        Return the username this connection is authenticated for.  If the
+        session is not authenticated (or authentication failed), this method
+        returns C{None}.
+
+        @return: username that was authenticated, or C{None}.
+        @rtype: string
+        """
+        return self.username
+
     def auth_publickey(self, username, key, event):
         """
         Authenticate to the server using a private key.  The key is used to
@@ -334,6 +347,8 @@ class Transport (BaseTransport):
             self._log(DEBUG, 'Auth rejected because the client attempted to change username in mid-flight')
             self._disconnect_no_more_auth()
             return
+        self.auth_username = username
+
         if method == 'none':
             result = self.check_auth_none(username)
         elif method == 'password':
@@ -390,7 +405,7 @@ class Transport (BaseTransport):
                 m.add_boolean(1)
             else:
                 m.add_boolean(0)
-            self.auth_fail_count += 1
+                self.auth_fail_count += 1
         self._send_message(m)
         if self.auth_fail_count >= 10:
             self._disconnect_no_more_auth()
@@ -411,6 +426,8 @@ class Transport (BaseTransport):
             pass
         self._log(INFO, 'Authentication failed.')
         self.authenticated = False
+        # FIXME: i don't think we need to close() necessarily here
+        self.username = None
         self.close()
         if self.auth_event != None:
             self.auth_event.set()
diff --git a/paramiko/channel.py b/paramiko/channel.py
index 44672d9..2a7bd20 100644
--- a/paramiko/channel.py
+++ b/paramiko/channel.py
@@ -70,7 +70,7 @@ class Channel (object):
         self.eof_sent = 0
         self.in_buffer = ''
         self.timeout = None
-        self.closed = 0
+        self.closed = False
         self.lock = threading.Lock()
         self.in_buffer_cv = threading.Condition(self.lock)
         self.out_buffer_cv = threading.Condition(self.lock)
@@ -302,7 +302,7 @@ class Channel (object):
                 m.add_byte(chr(MSG_CHANNEL_CLOSE))
                 m.add_int(self.remote_chanid)
                 self.transport._send_message(m)
-                self.closed = 1
+                self._set_closed()
                 self.transport._unlink_channel(self.chanid)
         finally:
             self.lock.release()
@@ -723,6 +723,11 @@ class Channel (object):
     def _log(self, level, msg):
         self.logger.log(level, msg)
 
+    def _set_closed(self):
+        self.closed = True
+        self.in_buffer_cv.notifyAll()
+        self.out_buffer_cv.notifyAll()
+
     def _send_eof(self):
         if self.eof_sent:
             return
@@ -815,7 +820,7 @@ class Channel (object):
     def _unlink(self):
         if self.closed or not self.active:
             return
-        self.closed = 1
+        self._set_closed()
         self.transport._unlink_channel(self.chanid)
 
     def _check_add_window(self, n):
diff --git a/paramiko/common.py b/paramiko/common.py
index e5aaaf8..88e8b1a 100644
--- a/paramiko/common.py
+++ b/paramiko/common.py
@@ -62,7 +62,10 @@ randpool.randomize()
 
 import sys
 if sys.version_info < (2, 3):
-    import logging22 as logging
+    try:
+        import logging
+    except:
+        import logging22 as logging
     import select
     PY22 = True
 else:
diff --git a/paramiko/pkey.py b/paramiko/pkey.py
index 7b8afcb..fa3cccc 100644
--- a/paramiko/pkey.py
+++ b/paramiko/pkey.py
@@ -237,7 +237,7 @@ class PKey (object):
         lines = f.readlines()
         f.close()
         start = 0
-        while (lines[start].strip() != '-----BEGIN ' + tag + ' PRIVATE KEY-----') and (start < len(lines)):
+        while (start < len(lines)) and (lines[start].strip() != '-----BEGIN ' + tag + ' PRIVATE KEY-----'):
             start += 1
         if start >= len(lines):
             raise SSHException('not a valid ' + tag + ' private key file')
diff --git a/paramiko/transport.py b/paramiko/transport.py
index bc3338c..29f59e8 100644
--- a/paramiko/transport.py
+++ b/paramiko/transport.py
@@ -636,10 +636,11 @@ class BaseTransport (threading.Thread):
 
         # check host key if we were given one
         if (hostkeytype is not None) and (hostkey is not None):
-            type, key = self.get_remote_server_key()
-            if (type != hostkeytype) or (key != hostkey):
-                print repr(type) + ' - ' + repr(hostkeytype)
-                print repr(key) + ' - ' + repr(hostkey)
+            keytype, key = self.get_remote_server_key()
+            if (keytype != hostkeytype) or (key != hostkey):
+                self._log(DEBUG, 'Bad host key from server')
+                self._log(DEBUG, 'Expected: %s: %s' % (repr(hostkeytype), repr(hostkey)))
+                self._log(DEBUG, 'Got     : %s: %s' % (repr(keytype), repr(key)))
                 raise SSHException('Bad host key from server')
             self._log(DEBUG, 'Host key verified (%s)' % hostkeytype)
 
@@ -920,6 +921,8 @@ class BaseTransport (threading.Thread):
             self._log(DEBUG, util.tb_strings())
             self.saved_exception = e
         _active_threads.remove(self)
+        for chan in self.channels.values():
+            chan._unlink()
         if self.active:
             self.active = False
             if self.completion_event != None: