diff --git a/plone/app/discussion/comment.py b/plone/app/discussion/comment.py
index 9373a77..9b849b2 100644
--- a/plone/app/discussion/comment.py
+++ b/plone/app/discussion/comment.py
@@ -1,5 +1,6 @@
 """The default comment class and factory.
 """
+import time
 from datetime import datetime
 from zope.interface import implements
 from zope.component.factory import Factory
@@ -42,8 +43,9 @@ class Comment(Explicit, Traversable, RoleManager, Owned):
     author_name = None
     author_email = None
     
-    def __init__(self, id=0, conversation=None, **kw):
-        self.comment_id = id
+    def __init__(self, conversation=None, **kw):
+        self.comment_id = long(time.time() * 1e6)
+
         self.__parent__ = conversation
         self.creation_date = self.modification_date = datetime.now()
         
diff --git a/plone/app/discussion/conversation.py b/plone/app/discussion/conversation.py
index cfd35fe..95534c7 100644
--- a/plone/app/discussion/conversation.py
+++ b/plone/app/discussion/conversation.py
@@ -20,6 +20,13 @@ from zope.annotation.interfaces import IAnnotatable
 from BTrees.OIBTree import OIBTree
 from BTrees.IOBTree import IOBTree
 from BTrees.IIBTree import IIBTree, IISet
+try:
+    from BTrees.LOBTree import LOBTree
+    from BTrees.LLBTree import LLBTree # TODO: Does this even exist?
+except ImportError:
+    from BTrees.OOBTree import OOBTree as LOBTree
+    from BTrees.OOBTree import OOSet as LLSet
+
 
 from Acquisition import Explicit
 
@@ -42,11 +49,11 @@ class Conversation(Persistent, Explicit):
         self._last_comment_date = None
         
         # id -> comment - find comment by id
-        self._comments = IOBTree()  
+        self._comments = LOBTree()  
         
         # id -> IISet (children) - find all children for a given comment. 0 signifies root.
-        self._children = IOBTree()
-    
+        self._children = LOBTree()
+        
     def getId(self):
         """
         """
@@ -64,7 +71,6 @@ class Conversation(Persistent, Explicit):
     
     @property
     def last_comment_date(self):
-        # TODO
         return self._last_comment_date
     
     @property
@@ -76,10 +82,13 @@ class Conversation(Persistent, Explicit):
         return self._comments.values()
     
     def getThreads(self, start=0, size=None, root=None, depth=None):
+        # TODO:
         return self._comments.values()
     
     def addComment(self, comment):
-        id = len(self._comments) + 1
+        id = comment.comment_id
+        if id in self._comments:
+            id = max(self._comments.keys()) +1
         self._comments[id] = comment
         comment.comment_id = id
         
@@ -92,7 +101,7 @@ class Conversation(Persistent, Explicit):
         
         reply_to = comment.in_reply_to
         if not reply_to in self._children:
-            self._children[reply_to] = IISet()
+            self._children[reply_to] = LLSet()
         self._children[reply_to].insert(id)
         
     # Dict API
diff --git a/plone/app/discussion/tests/test_api.py b/plone/app/discussion/tests/test_api.py
index 2e28195..80ee97b 100644
--- a/plone/app/discussion/tests/test_api.py
+++ b/plone/app/discussion/tests/test_api.py
@@ -37,7 +37,7 @@ class ConversationTest(TestCase):
         conversation.addComment(comment)
         
         # Check that the conversation methods return the correct data
-        self.assertEquals(comment.id, '1')
+        self.assert_(isinstance(comment.comment_id, long))
         self.assertEquals(len(conversation.getComments()), 1)
         self.assertEquals(len(conversation.getThreads()), 1)
         self.assertEquals(conversation.total_comments, 1)