I've recently upgraded to Ubuntu 13.10 which has a known bug that makes it impossible to change keyboard layout via Alt+Shift. I installed this patch which made it possible to switch layouts again. The problem I'm facing now is that it is still impossible to switch keyboard layout when I lock (Ctrl+Alt+L) system and press Alt+Shift. This way if I lock system with wrong layout enabled, I can't switch it to enter the password and unlock PC. I can still change layout by clicking on the layout indicator. I'll be thankful for suggestions on solving this.