use plural forms (ngettext) in a string. please convert your strings that way

src/chat.py

@@ -109,12 +109,12 @@ class Chat:
 		chat = self.names[jid]
 		if len(self.xmls) > 1: # if more than one tab in the same window
 			if self.widget_name == 'tabbed_chat_window':
-				chat = 'Chat'
+				chat = _('Chat')
 			elif self.widget_name == 'groupchat_window':
-				chat = 'Groupchat'
+				chat = _('Group Chat')
 		title = start + chat
 		if len(gajim.connections) >= 2: # if we have 2 or more accounts
-			title = title + _(' (account: ') + self.account + ')'
+			title = title + ' (' + _('account: ') + self.account + ')'
 
 		self.window.set_title(title)
 

src/common/i18n.py

@@ -1,5 +1,5 @@
 ##	common/i18n.py
-##
+## -*- coding: utf-8 -*-
 ## Gajim Team:
 ##  - Yann Le Boulanger <asterix@lagaule.org>
 ##  - Vincent Hanquez <tab@snarc.org>
@@ -17,8 +17,8 @@
 ## GNU General Public License for more details.
 ##
 
-APP='gajim'
-DIR='../po'
+APP = 'gajim'
+DIR = '../po'
 
 import locale
 import gettext
@@ -36,5 +36,4 @@ def init():
 def _(s):
 	if s == '':
 		return s
-	assert s
 	return _translation.gettext(s)

src/dialogs.py

@@ -487,16 +487,12 @@ class ConfirmationDialogCheck(ConfirmationDialog):
 	def __init__(self, pritext, sectext='', checktext = ''):
 		HigDialog.__init__(self, None, pritext, sectext,
 			gtk.STOCK_DIALOG_WARNING, [ [gtk.STOCK_CANCEL, gtk.RESPONSE_CANCEL] ])
+		
 		# add ok button manually, because we need to focus on it 
-		ok_button = self.add_button (gtk.STOCK_OK, gtk.RESPONSE_OK)
+		ok_button = self.add_button(gtk.STOCK_OK, gtk.RESPONSE_OK)
 		self.checkbutton = gtk.CheckButton(checktext)
 		self.vbox.pack_start(self.checkbutton, expand=False, fill=True)
 		ok_button.grab_focus()
-	# override this method not to destroy the dialog
-	def get_response(self):
-		self.show_all()
-		response = gtk.Dialog.run(self)
-		return response
 	
 	def is_checked(self):
 		''' Get active state of the checkbutton '''

src/groupchat_window.py

@@ -30,6 +30,7 @@ import gtkgui_helpers
 from gajim import Contact
 from common import gajim
 from common import helpers
+from gettext import ngettext
 from common import i18n
 
 _ = i18n._
@@ -111,7 +112,6 @@ class GroupchatWindow(chat.Chat):
 
 	def on_groupchat_window_delete_event(self, widget, event):
 		"""close window"""
-		stop_propagation = False
 		for room_jid in self.xmls:
 			if time.time() - gajim.last_message_time[self.account][room_jid] < 2:
 				dialog = dialogs.ConfirmationDialog(
@@ -119,39 +119,44 @@ class GroupchatWindow(chat.Chat):
 			_('If you close this window, this message will be lost.')
 					)
 				if dialog.get_response() != gtk.RESPONSE_OK:
-					stop_propagation = True #stop the propagation of the event
-		if not stop_propagation and self.confirm_close:
-			if len(self.xmls) >=2:
-				names = ''
+					dialog.destroy()
+					return True # stop the propagation of the delete event
+		
+		if self.confirm_close:
+			name = ''
+			names = ''
+			if len(self.xmls) >= 2:
 				for room in self.xmls:
 					if names != '':
 						names += ', '
 					names += gajim.get_nick_from_jid(room)
-					pritext = _('Are you sure you want to leave rooms "%s"?') \
-						% names
-					sectext = \
-		_('If you close this window, you will be disconnected from these rooms.')
 			else:
 				name = gajim.get_nick_from_jid(room_jid)
-				pritext = _('Are you sure you want to leave room "%s"?') \
-					% name
-				sectext = \
-		_('If you close this window, you will be disconnected from the room.')
+		
+			pritext = ngettext('Are you sure you want to leave room "%s"?' % name,
+				'Are you sure you want to leave rooms "%s"?' % names, len(self.xmls))
+			
+			sectext = ngettext(
+			'If you close this window, you will be disconnected from this room.',
+			'If you close this window, you will be disconnected from these rooms.',
+				len(self.xmls))
+			
 			dialog = dialogs.ConfirmationDialogCheck(pritext, sectext,
 				_('Do not ask me again') )
+			
 			if dialog.get_response() != gtk.RESPONSE_OK:
-				stop_propagation = True 
+				return True  # stop propagation of the delete event
+			
 			if dialog.is_checked():
 				gajim.config.set('confirm_close_muc', False)
-			dialog.destroy()
-		if stop_propagation:
-			return True
+				dialog.destroy()
+
 		for room_jid in self.xmls:
 			gajim.connections[self.account].send_gc_status(self.nicks[room_jid],
 				room_jid, 'offline', 'offline')
 
 		if gajim.config.get('saveposition'):
-		# save window position and size
+			# save window position and size
 			gajim.config.set('gc-hpaned-position', self.hpaned_position)
 			x, y = self.window.get_position()
 			gajim.config.set('gc-x-position', x)