diff --git a/offlineimap/folder/Base.py b/offlineimap/folder/Base.py
index 3913367..7445875 100644
--- a/offlineimap/folder/Base.py
+++ b/offlineimap/folder/Base.py
@@ -524,13 +524,21 @@ class BaseFolder:
 
         raise NotImplementedError
 
-    def savemessagelabels(self, uid, labels, ignorelabels=set(), mtime=0):
+    def savemessagelabels(self, uid, labels, ignorelabels=None, mtime=0):
         """Sets the specified message's labels to the given set.
 
         Note that this function does not check against dryrun settings,
         so you need to ensure that it is never called in a
         dryrun mode."""
 
+        """
+        If this function is implemented,
+        then it should include this code:
+
+        if ignorelabels is None:
+            ignorelabels = set()
+        """
+
         raise NotImplementedError
 
     def addmessagelabels(self, uid, labels):
diff --git a/offlineimap/folder/Gmail.py b/offlineimap/folder/Gmail.py
index 750ff46..af236e1 100644
--- a/offlineimap/folder/Gmail.py
+++ b/offlineimap/folder/Gmail.py
@@ -56,7 +56,7 @@ class GmailFolder(IMAPFolder):
 
         # Labels to be left alone
         ignorelabels = self.repository.account.getconf('ignorelabels', '')
-        self.ignorelabels = set([l for l in re.split(r'\s*,\s*', ignorelabels) if len(l)])
+        self.ignorelabels = set([v for v in re.split(r'\s*,\s*', ignorelabels) if len(v)])
 
     def getmessage(self, uid):
         """Retrieve message with UID from the IMAP server (incl body).  Also
diff --git a/offlineimap/folder/GmailMaildir.py b/offlineimap/folder/GmailMaildir.py
index 4114dd4..ebefd1b 100644
--- a/offlineimap/folder/GmailMaildir.py
+++ b/offlineimap/folder/GmailMaildir.py
@@ -133,12 +133,15 @@ class GmailMaildirFolder(MaildirFolder):
         self.messagelist[uid]['labels'] = labels
         return ret
 
-    def savemessagelabels(self, uid, labels, ignorelabels=set()):
+    def savemessagelabels(self, uid, labels, ignorelabels=None):
         """Change a message's labels to `labels`.
 
         Note that this function does not check against dryrun settings,
         so you need to ensure that it is never called in a dryrun mode."""
 
+        if ignorelabels is None:
+            ignorelabels = set()
+
         filename = self.messagelist[uid]['filename']
         filepath = os.path.join(self.getfullname(), filename)
 
diff --git a/offlineimap/folder/IMAP.py b/offlineimap/folder/IMAP.py
index 53004a8..342c102 100644
--- a/offlineimap/folder/IMAP.py
+++ b/offlineimap/folder/IMAP.py
@@ -91,7 +91,7 @@ class IMAPFolder(BaseFolder):
         name = self.getfullname()
         if self.repository.account.utf_8_support:
             name = imaputil.utf8_IMAP(name)
-        return name
+        return imaputil.foldername_to_imapname(name)
 
     # Interface from BaseFolder
     def suggeststhreads(self):
diff --git a/offlineimap/folder/LocalStatus.py b/offlineimap/folder/LocalStatus.py
index d1e2eb8..4f8d42d 100644
--- a/offlineimap/folder/LocalStatus.py
+++ b/offlineimap/folder/LocalStatus.py
@@ -190,13 +190,16 @@ class LocalStatusFolder(BaseFolder):
                 os.close(fd)
 
     # Interface from BaseFolder
-    def savemessage(self, uid, content, flags, rtime, mtime=0, labels=set()):
+    def savemessage(self, uid, content, flags, rtime, mtime=0, labels=None):
         """Writes a new message, with the specified uid.
 
         See folder/Base for detail. Note that savemessage() does not
         check against dryrun settings, so you need to ensure that
         savemessage is never called in a dryrun mode."""
 
+        if labels is None:
+            labels = set()
+
         if uid < 0:
             # We cannot assign a uid.
             return uid
diff --git a/offlineimap/folder/LocalStatusSQLite.py b/offlineimap/folder/LocalStatusSQLite.py
index 5292463..27a9a81 100644
--- a/offlineimap/folder/LocalStatusSQLite.py
+++ b/offlineimap/folder/LocalStatusSQLite.py
@@ -323,13 +323,16 @@ class LocalStatusSQLiteFolder(BaseFolder):
     #        assert False,"getmessageflags() called on non-existing message"
 
     # Interface from BaseFolder
-    def savemessage(self, uid, content, flags, rtime, mtime=0, labels=set()):
+    def savemessage(self, uid, content, flags, rtime, mtime=0, labels=None):
         """Writes a new message, with the specified uid.
 
         See folder/Base for detail. Note that savemessage() does not
         check against dryrun settings, so you need to ensure that
         savemessage is never called in a dryrun mode."""
 
+        if labels is None:
+            labels = set()
+
         if uid < 0:
             # We cannot assign a uid.
             return uid
diff --git a/offlineimap/folder/Maildir.py b/offlineimap/folder/Maildir.py
index f275436..f06217b 100644
--- a/offlineimap/folder/Maildir.py
+++ b/offlineimap/folder/Maildir.py
@@ -270,7 +270,7 @@ class MaildirFolder(BaseFolder):
         filepath = os.path.join(self.getfullname(), filename)
         return os.path.getmtime(filepath)
 
-    def new_message_filename(self, uid, flags=set(), date=None):
+    def new_message_filename(self, uid, flags=None, date=None):
         """Creates a new unique Maildir filename
 
         :param uid: The UID`None`, or a set of maildir flags
@@ -278,6 +278,9 @@ class MaildirFolder(BaseFolder):
         :param flags: (optional) Date
         :returns: String containing unique message filename"""
 
+        if flags is None:
+            flags = set()
+
         timeval, timeseq = _gettimeseq(date)
         uniq_name = '%d_%d.%d.%s,U=%d,FMD5=%s%s2,%s' % \
                     (timeval, timeseq, os.getpid(), socket.gethostname(),
diff --git a/offlineimap/imaputil.py b/offlineimap/imaputil.py
index 63aae67..4083d34 100644
--- a/offlineimap/imaputil.py
+++ b/offlineimap/imaputil.py
@@ -73,16 +73,16 @@ def flagsplit(s):
     return imapsplit(s[1:-1])
 
 
-def __options2hash(list):
-    """convert list [1,2,3,4,5,6] to {1:2, 3:4, 5:6}"""
+def __options2hash(l_list):
+    """convert l_list [1,2,3,4,5,6] to {1:2, 3:4, 5:6}"""
 
     # effectively this does dict(zip(l[::2],l[1::2])), however
     # measurements seemed to have indicated that the manual variant is
     # faster for mosly small lists.
     retval = {}
     counter = 0
-    while counter < len(list):
-        retval[list[counter]] = list[counter + 1]
+    while counter < len(l_list):
+        retval[l_list[counter]] = l_list[counter + 1]
         counter += 2
     __debug("__options2hash returning:", retval)
     return retval
@@ -435,3 +435,23 @@ def imap4_utf_7(name):
 
 
 codecs.register(imap4_utf_7)
+
+
+def foldername_to_imapname(folder_name):
+    """
+    This function returns the folder_name ready to send to the
+    IMAP server. It tests if the folder_name has special characters
+    Then, quote it.
+    Args:
+        folder_name: Folder's name
+
+    Returns: The folder_name quoted if needed
+
+    """
+    # If name includes some of these characters, quote it
+    atom_specials = [' ', '/', '(', ')', '{', '}']
+
+    if any((c in atom_specials) for c in folder_name):
+        folder_name = '"' + folder_name + '"'
+
+    return folder_name
\ No newline at end of file
diff --git a/offlineimap/repository/__init__.py b/offlineimap/repository/__init__.py
index ad2edf2..171f6aa 100644
--- a/offlineimap/repository/__init__.py
+++ b/offlineimap/repository/__init__.py
@@ -32,7 +32,7 @@ class Repository:
     def __new__(cls, account, reqtype):
         """
         :param account: :class:`Account`
-        :param regtype: 'remote', 'local', or 'status'"""
+        :param reqtype: 'remote', 'local', or 'status'"""
 
         if reqtype == 'remote':
             name = account.getconf('remoterepository')
@@ -81,6 +81,6 @@ class Repository:
         executed instead of this stub
 
         :param account: :class:`Account`
-        :param regtype: 'remote', 'local', or 'status'
+        :param reqtype: 'remote', 'local', or 'status'
         """
         pass
diff --git a/offlineimap/threadutil.py b/offlineimap/threadutil.py
index 2673542..fd4b10b 100644
--- a/offlineimap/threadutil.py
+++ b/offlineimap/threadutil.py
@@ -78,17 +78,6 @@ def monitor():
     """An infinite "monitoring" loop watching for finished ExitNotifyThread's.
 
     This one is supposed to run in the main thread.
-    :param callback: the function to call when a thread terminated. That
-                     function is called with a single argument -- the
-                     ExitNotifyThread that has terminated. The monitor will
-                     not continue to monitor for other threads until
-                     'callback' returns, so if it intends to perform long
-                     calculations, it should start a new thread itself -- but
-                     NOT an ExitNotifyThread, or else an infinite loop
-                     may result.
-                     Furthermore, the monitor will hold the lock all the
-                     while the other thread is waiting.
-    :type callback:  a callable function
     """
 
     global exitedThreads