diff --git a/services/presence/Makefile.am b/services/presence/Makefile.am
index 57de87d9..4e286240 100644
--- a/services/presence/Makefile.am
+++ b/services/presence/Makefile.am
@@ -13,6 +13,7 @@ sugar_PYTHON = \
 	buddyiconcache.py \
 	linklocal_plugin.py \
 	presenceservice.py \
+	psutils.py \
 	server_plugin.py
 
 bin_SCRIPTS = sugar-presence-service
diff --git a/services/presence/buddy.py b/services/presence/buddy.py
index a5c18ed5..4906b9d2 100644
--- a/services/presence/buddy.py
+++ b/services/presence/buddy.py
@@ -170,7 +170,10 @@ class Buddy(DBusGObject):
         props['owner'] = self.props.owner
         props['key'] = self.props.key
         props['color'] = self.props.color
-        props['current-activity'] = self.props.current_activity
+        if self.props.current_activity:
+            props['current-activity'] = self.props.current_activity
+        else:
+            props['current-activity'] = ""
         return props
 
     # methods
diff --git a/services/presence/presenceservice.py b/services/presence/presenceservice.py
index d4ad38c3..bb000945 100644
--- a/services/presence/presenceservice.py
+++ b/services/presence/presenceservice.py
@@ -89,8 +89,7 @@ class PresenceService(dbus.service.Object):
 
     def _contact_online(self, tp, handle, props):
         new_buddy = False
-        key = props['key']
-        buddy = self._buddies.get(key)
+        buddy = self._buddies.get(props["key"])
         if not buddy:
             # we don't know yet this buddy
             objid = self._get_next_object_id()
@@ -253,26 +252,33 @@ class PresenceService(dbus.service.Object):
     def GetActivities(self):
         ret = []
         for act in self._activities.values():
-            ret.append(act.object_path())
+            if act.props.valid:
+                ret.append(act.object_path())
         return ret
 
     @dbus.service.method(_PRESENCE_INTERFACE, in_signature="s", out_signature="o")
     def GetActivityById(self, actid):
         if self._activities.has_key(actid):
-            return self._activities[actid].object_path()
+            act = self._activities[actid]
+            if act.props.valid:
+                return act.object_path()
         raise NotFoundError("The activity was not found.")
 
     @dbus.service.method(_PRESENCE_INTERFACE, out_signature="ao")
     def GetBuddies(self):
         ret = []
         for buddy in self._buddies.values():
-            ret.append(buddy.object_path())
+            if buddy.props.valid:
+                ret.append(buddy.object_path())
         return ret
 
     @dbus.service.method(_PRESENCE_INTERFACE, in_signature="ay", out_signature="o")
     def GetBuddyByPublicKey(self, key):
+        key = psutils.bytes_to_string(key)
         if self._buddies.has_key(key):
-            return self._buddies[key].object_path()
+            buddy = self._buddies[key]
+            if buddy.props.valid:
+                return buddy.object_path()
         raise NotFoundError("The buddy was not found.")
 
     @dbus.service.method(_PRESENCE_INTERFACE, out_signature="o")
diff --git a/services/presence/psutils.py b/services/presence/psutils.py
new file mode 100644
index 00000000..995ea3ab
--- /dev/null
+++ b/services/presence/psutils.py
@@ -0,0 +1,26 @@
+# Copyright (C) 2007, Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+
+def bytes_to_string(bytes):
+    # Handle both DBus byte arrays and strings
+    try:
+        # DBus Byte array
+        ret = ''.join([chr(item) for item in bytes])
+    except TypeError:
+        # Python string
+        ret = ''.join([str(item) for item in bytes])
+    return ret
diff --git a/services/presence/server_plugin.py b/services/presence/server_plugin.py
index ffa2ab21..c674343b 100644
--- a/services/presence/server_plugin.py
+++ b/services/presence/server_plugin.py
@@ -25,6 +25,7 @@ from buddyiconcache import BuddyIconCache
 import logging
 import os
 import hashlib
+import psutils
 
 from telepathy.client import ConnectionManager, ManagerRegistry, Connection, Channel
 from telepathy.interfaces import (
@@ -304,7 +305,7 @@ class ServerPlugin(gobject.GObject):
         # Set our OLPC buddy properties
         props = {}
         props['color'] = self._owner.props.color
-        props['key'] = self._owner.props.key
+        props['key'] = dbus.ByteArray(self._owner.props.key)
         try:
             self._conn[CONN_INTERFACE_BUDDY_INFO].SetProperties(props)
         except dbus.DBusException, e:
@@ -405,15 +406,8 @@ class ServerPlugin(gobject.GObject):
         if not props.has_key('key'):
             raise InvalidBuddyError("no key")
 
-        # Convert from D-Bus array types to a standard python byte array
-        key = ""
-        for item in props["key"]:
-            try:
-                # int type
-                key = key + "%s" % chr(item)
-            except TypeError:
-                # string type
-                key = key + str(item)
+        # Convert key from dbus byte array to python string
+        props["key"] = psutils.bytes_to_string(props["key"])
 
         jid = self._conn[CONN_INTERFACE].InspectHandles(CONNECTION_HANDLE_TYPE_CONTACT, [handle])[0]
         nick = self._conn[CONN_INTERFACE_ALIASING].RequestAliases([handle])[0]