diff --git a/launch.sh b/launch.sh
index f61870f69..bcb968553 100755
--- a/launch.sh
+++ b/launch.sh
@@ -1,3 +1,3 @@
 #!/bin/sh
 cd "$(dirname $0)/src"
-exec python -t gajim.py $@
+exec python -OOt gajim.py $@
diff --git a/src/roster_window.py b/src/roster_window.py
index 535086bfa..e30492daa 100644
--- a/src/roster_window.py
+++ b/src/roster_window.py
@@ -404,9 +404,6 @@ class RosterWindow:
 					gajim.groups[account][group] = {'expand': is_expanded}
 
 		assert len(added_iters), '%s has not been added to roster!' % contact.jid
-#		assert all(self.model[titer][C_JID] == contact.jid and \
-#			self.model[titer][C_ACCOUNT] == account for titer in added_iters), \
-#			"Iters invalidated for %s" % contact.jid
 		return added_iters
 
 	def _remove_entity(self, contact, account, groups=None):