diff --git a/shell/model/Owner.py b/shell/model/Owner.py
index ec62ba52..3bf3a555 100644
--- a/shell/model/Owner.py
+++ b/shell/model/Owner.py
@@ -2,7 +2,6 @@ import os
 import random
 import base64
 import time
-import gobject
 
 import conf
 from sugar import env
@@ -19,12 +18,9 @@ class ShellOwner(object):
 	"""Class representing the owner of this machine/instance.  This class
 	runs in the shell and serves up the buddy icon and other stuff.  It's the
 	server portion of the Owner, paired with the client portion in Buddy.py."""
-	def __init__(self, shell_model):
+	def __init__(self):
 		profile = conf.get_profile()
 
-		self._shell_model = shell_model
-		self._shell_model.connect('activity-changed', self.__activity_changed_cb)
-
 		self._nick = profile.get_nick_name()
 		user_dir = profile.get_path()
 
@@ -82,33 +78,29 @@ class ShellOwner(object):
 	def __update_advertised_current_activity_cb(self):
 		self._last_activity_update = time.time()
 		self._pending_activity_update_timer = None
-		actid = self._pending_activity_update
-		if not actid:
-			actid = ""
-		self._service.set_published_value('curact', dbus.String(actid))
+		if self._pending_activity_update:
+			logging.debug("*** Updating current activity to %s" % self._pending_activity_update)
+			self._service.set_published_value('curact', dbus.String(self._pending_activity_update))
 		return False
 
-	def __activity_changed_cb(self, shell_model, activity_id):
+	def set_current_activity(self, activity_id):
 		"""Update our presence service with the latest activity, but no
 		more frequently than every 30 seconds"""
-		if activity_id == self._pending_activity_update:
-			return
 		self._pending_activity_update = activity_id
+		# If there's no pending update, we must not have updated it in the
+		# last 30 seconds (except for the initial update, hence we also check
+		# for the last update)
+		if not self._pending_activity_update_timer or time.time() - self._last_activity_update > 30:
+			self.__update_advertised_current_activity_cb()
+			return
 
 		# If we have a pending update already, we have nothing left to do
 		if self._pending_activity_update_timer:
 			return
 
-		# If there's no pending update, we must not have updated it in the
-		# last 30 seconds (except for the initial update, hence we also check
-		# for the last update)
-		if time.time() - self._last_activity_update > 30:
-			self.__update_advertised_current_activity_cb()
-			return
-
 		# Otherwise, we start a timer to update the activity at the next
 		# interval, which should be 30 seconds from the last update, or if that
 		# is in the past already, then now
-		next = int(30 - max(0, time.time() - self._last_activity_update))
+		next = 30 - max(30, time.time() - self._last_activity_update)
 		self._pending_activity_update_timer = gobject.timeout_add(next * 1000,
 				self.__update_advertised_current_activity_cb)
diff --git a/shell/model/ShellModel.py b/shell/model/ShellModel.py
index 024fd530..9b6d5989 100644
--- a/shell/model/ShellModel.py
+++ b/shell/model/ShellModel.py
@@ -2,22 +2,15 @@ from sugar.presence import PresenceService
 from model.Friends import Friends
 from model.MeshModel import MeshModel
 from model.Owner import ShellOwner
-import gobject
-
-class ShellModel(gobject.GObject):
-	__gsignals__ = {
-		'activity-changed':  (gobject.SIGNAL_RUN_FIRST,
-							 gobject.TYPE_NONE, ([gobject.TYPE_PYOBJECT]))
-	}
 
+class ShellModel:
 	def __init__(self):
-		gobject.GObject.__init__(self)
 		self._current_activity = None
 
 		PresenceService.start()
 		self._pservice = PresenceService.get_instance()
 
-		self._owner = ShellOwner(self)
+		self._owner = ShellOwner()
 		self._owner.announce()
 		self._friends = Friends()
 		self._mesh = MeshModel()
@@ -36,7 +29,7 @@ class ShellModel(gobject.GObject):
 
 	def set_current_activity(self, activity_id):
 		self._current_activity = activity_id
-		self.emit('activity-changed', activity_id)
+		self._owner.set_current_activity(activity_id)
 
 	def get_current_activity(self):
 		return self._current_activity